Flared energy absorbing system and method

ABSTRACT

An energy absorbing system with one or more energy absorbing assemblies is provided to reduce or eliminate the severity of a collision between a moving motor vehicle and a roadside hazard. The energy absorbing system may be installed adjacent to a gore area and other relatively wide roadside hazards. One end of the system facing oncoming traffic is relatively narrow. The width at an opposite end of the system may be varied to accommodate relatively wide or large roadside hazards. A sled assembly may be provided with a cutter plate such that a collision by the motor vehicle with the sled assembly will result in the cutter plate tearing or ripping the energy absorbing element to dissipate energy from the motor vehicle collision.

RELATED APPLICATIONS

This application claims the benefit, under 35 U.S.C. § 119(e), ofpreviously filed provisional application Flared Energy Absorbing Systemand Method, Ser. No. 60/397,529, filed Jul. 22, 2002.

This application is a continuation-in-part of divisional applicationU.S. Ser. No. 09/832,162 filed Apr. 9, 2001 by James R. Albrittonentitled Energy Absorbing System for Fixed Roadside Hazards, now U.S.Pat. No. ______.

Divisional application U.S. Ser. No. 09/832,162 filed Apr. 9, 2001,claims priority from continuation-in-part application U.S. Ser. No.09/356,060 filed Jul. 19, 1999 by James R. Albritton entitled EnergyAbsorbing System for Fixed Roadside Hazards now U.S. Pat. No. 6,293,727.

TECHNICAL FIELD OF THE INVENTION

This invention relates in general to energy absorbing systems, and moreparticularly to an energy absorbing system used to reduce severity of acollision between a moving motor vehicle and a hazard located adjacentto a roadway.

BACKGROUND OF THE INVENTION

Various impact attenuation devices and energy absorbing systems havebeen used to prevent or reduce damage resulting from a collision betweena moving motor vehicle and a fixed roadside hazard or obstacle. Examplesof prior impact attenuation devices and energy absorbing systems includecrash cushions or crash barriers with various structures and containershaving crushable elements. Other crash barriers rely on inertia forcesgenerated when material such as sand is accelerated during an impact toabsorb energy.

Some of these devices and systems have been developed for use at narrowroadside hazards or obstacles such as at the end of a median barrier,end of a barrier extending along the edge of a roadway, large sign postsadjacent to a roadway, and bridge pillars or center piers. Such impactattenuation devices and energy absorbing systems are installed in aneffort to minimize the extent of personal injury as well as damage to animpacting vehicle and any structure or equipment associated with theroadside hazard.

Examples of general purpose impact attenuation devices are shown in U.S.Pat. No. 5,011,326 entitled Narrow Stationary Impact Attenuation System;U.S. Pat. No. 4,352,484 entitled Shear Action and Compression EnergyAbsorber; U.S. Pat. No. 4,645,375 entitled Stationary Impact AttenuationSystem; and U.S. Pat. No. 3,944,187 entitled Roadway Impact Attenuator.Examples of specialized stationary energy absorbing systems are shown inU.S. Pat. No. 4,928,928 entitled Guardrail Extruder Terminal and U.S.Pat. No. 5,078,366 entitled Guardrail Extruder Terminal.

Examples of impact attenuation devices and energy absorbing systemsappropriate for use on a slow moving or stopped highway service vehicleare shown in U.S. Pat. No. 5,248,129 entitled Energy Absorbing RoadsideCrash Barrier; U.S. Pat. No. 5,199,755 entitled Vehicle ImpactAttenuating Device; U.S. Pat. No. 4,711,481 entitled Vehicle ImpactAttenuating Device; U.S. Pat. No. 4,008,915 entitled Impact Barrier forVehicles.

Recommended procedures for evaluating performance of various types ofhighway safety devices including crash cushions is presented in NationalCooperative Highway Research Program (NCHRP) Report 350. A crash cushionis generally defined as a device designed to safely stop an impactingvehicle within a relatively short distance. NCHRP Report 350 furtherclassifies crash cushions as either “redirective” or “nonredirective”. Aredirective crash cushion is designed to contain and redirect a vehicleimpacting downstream from a nose or end of the crash cushion facingoncoming traffic extending from a roadside hazard. Nonredirective crashcushions are designed to contain and capture a vehicle impactingdownstream from the nose of the crash cushion. Redirective crashcushions are further classified as either “gating” or “nongating”devices. A gating crash cushion is one designed to allow controlledpenetration of a vehicle during impact between the nose of the crashcushion and the beginning of length of need (LON) of the crash cushion.A nongating crash cushion is designed to have redirection capabilitiesalong its entire length.

SUMMARY OF THE INVENTION

In accordance with teachings of the present invention, disadvantages andproblems associated with previous energy absorbing systems and impactattenuation devices have been substantially reduced or eliminated. Oneaspect of the present invention includes an energy absorbing systemwhich may be installed adjacent to relatively wide or large roadsidehazards to protect occupants of a vehicle during collision with suchroadside hazards. The system may include at least one energy absorbingassembly which dissipates energy from a vehicle impacting one end of thesystem opposite from a roadside hazard. The system may also includepanels and associated panel support frames to redirect a vehicleimpacting with either side of the system. At least a portion of thepanel support frames and panels may be flared or diverge relative toeach other to accommodate wide or large roadside hazards.

Another aspect of the present invention includes providing an energyabsorbing system having a plurality of panel support frames and panelswhich may be installed between a roadside hazard and oncoming traffic.At least one set or group of the panel support frames and panels may beslidably disposed relative to each other. At least another set or groupof the panel support frames and panels may be securely disposed relativeto each other. When a vehicle collides with one end of the energyabsorbing system facing oncoming traffic, the first group of panelsupport frames and panels may telescope or collapse relative to eachother. The first group of panel support frames, associated panels andother components of the energy absorbing system cooperate with eachother to absorb kinetic energy from the impacting vehicle and providedeceleration within acceptable limits to minimize injury to occupantswithin the vehicle. The panel support frames and panels also cooperatewith each other and other components of the energy absorbing system todirect vehicles away from the roadside hazard and back onto the roadwayfollowing a side impact with the energy absorbing system.

Technical advantages of the present invention include providing arelatively compact energy absorbing system having a variable width toaccommodate relatively large, wide roadside hazards and gore areas.Energy absorbing systems incorporating teachings of the presentinvention may be installed with either symmetric or asymmetricconfigurations. The energy absorbing system may be fabricated atrelatively low cost using conventional materials and processes that arewell known to the highway safety industry. The resulting system combinesinnovative structural and energy absorbing techniques that are highlypredictable and reliable. Panel support frames and panels may beinstalled on location to accommodate the width of an associated roadsidehazard or temporary work area.

In accordance with another aspect of the present invention, a crashcushion may be provided with multiple energy absorbing elements, a firstset of panels and a second set of panels disposed adjacently to aroadside hazard facing oncoming traffic. The spacing or angle betweenthe first set of panels and the second set of panels may be varied basedon the width of an associated roadside hazard without reducingperformance capabilities of the energy absorbing system. The energyabsorbing elements cooperate with each other to allow varying the amountof deceleration applied to a vehicle impacting one end of the crashcushion opposite from the roadside hazard. For example, the crashcushion may include a first, relatively soft portion to absorb impactfrom small, lightweight vehicles, a middle portion with increasedstiffness and a third or final portion with the greatest amount ofstiffness to absorb impact from heavy, high speed vehicles.

Further technical advantages of the present invention may includeproviding relatively low cost crash cushions and safety systems whichmeet the criteria of NCHRP Report 350 including Test Level 3Requirements and which may be installed adjacent to relatively wideroadside hazards such as five feet, eight feet or any other requiredwidth. A crash cushion having an energy absorbing assembly incorporatingteachings of the present invention may be satisfactorily used duringharsh weather conditions and is not sensitive to cold or moisture. Theenergy absorbing system may be easily installed, operated, inspected andmaintained. The system may be installed on new or existing asphalt orconcrete pads. Field assembly of impact attenuation devices and a basicenergy absorbing system are not required. Easily replaceable parts allowquick, low cost repair after nuisance hits and side impacts. Eliminationof easily crushed or easily bent materials further minimizes the effectof any damage from nuisance hits and/or side impacts with the crashcushion.

An energy absorbing system incorporating teachings of the presentinvention may be formed from at least one group of panel support framesand panels slidably disposed relative to each other and another group ofpanel support frames and panels which generally do not slide relative toeach other. The panel support frames and panels may be used tosatisfactorily absorb energy from a wide variety of vehicles collidingwith an energy absorbing system at various angles including side impactsand “reverse” angle side impacts.

Technical benefits of the present invention include an energy absorbingsystem that may be used with permanent roadside hazards or may be easilymoved from one temporary location (first work zone) to another temporarylocation (second work zone).

A further aspect of the present invention includes a crash cushion whichmay be used to minimize the results of a collision between a vehicle anda roadside hazard. The crash cushion may include an energy absorbingassembly extending in a first direction from a first end of the crashcushion. A plurality of panels may be located on a first side of theenergy absorbing assembly extending generally in the first direction.The panels preferably resist impact from a vehicle with the first side.The panels may have a first section that may be generally disposed at afirst orientation with respect to the first direction. The first sectionof panels may extend from the first end of the crash cushion to alocation along the first side. The panels may have a second sectionextending from the location at a second orientation with respect to thefirst direction. The second section of panels preferably intersects thefirst section of panels at an angle.

For some applications a portion of the first section of panels may havea first divergence from the first direction and at least a portion ofthe second section of panels may have a second divergence from the firstdirection. The first divergence may be unequal to the second divergence.Also, the second section of panels may include a moveable subsectionthat moves generally in the first direction when the energy absorbingassembly moves in the first direction. The second section of panels mayalso include a fixed subsection with the moveable subsection disposedcloser to the first end of the crash cushion than the fixed subsection.A plurality of panels may also be located on a second side of the energyabsorbing assembly opposite from the first side extending generally inthe first direction. The second side of panels may be disposedasymmetric with respect to the first side of panels.

Still another aspect of the present invention may include an energyabsorbing system to limit or reduce the results of a collision between avehicle and a roadside hazard. The system may include an energyabsorbing assembly extending in a first direction from a first end ofthe system. The energy absorbing system may have a first side located onone side of the energy absorbing assembly and a second side located onanother side of the energy absorbing assembly. The first side and thesecond side may each have respective panels which resist an impact by avehicle to the first side or the second side. The first and second sidesmay move generally in the first direction when a vehicle impacts thefirst end of the system. At least a portion of the first side may beuncoupled from the second side so that the uncoupled portions of thefirst side may be oriented with respect to the first directionindependently of the second side.

The energy absorbing system may include panel support frames coupled tothe panels of the first side and the second side. At least one of thepanel support frames may be coupled to a portion of the first side andseparated from other panel support frames coupled to the second side. Atleast one of the panel support frames coupled to the portion of thefirst side may bear upon or rest upon a concrete pad, portions of anassociated roadway or the ground adjacent to the energy absorbingsystem. The panel support frames that are coupled to the portion of thefirst side may be coupled to one or more outboard anchors to resistvehicle impacts to the first side.

Still another aspect of the present invention include a crash cushionoperable to minimize the results of a collision between a vehicle and aroadside hazard. The crash cushion may have an energy absorbing assemblyand panel support frames extending in a first direction from a first endof the crash cushion. The energy absorbing assembly may also be moveablein the first direction when a vehicle impacts the first end. The panelsupport frames may also be moveable in the first direction. Multiplepanels may be attached to the panel support frames extending generallyin the first direction. The panels may diverge from the first directionas the panels extend from the first end. Selected panels may havechannels attached thereto. A cable may extend through at least one ofthe channels along the selected panels. The cable may be anchored at alocation toward the first end of the crash cushion and also at alocation away from the first end of the crash cushion. The cables mayalso be coupled to the panel support frames. The energy absorbingassembly may include a moveable sled disposed at the first end of thecrash cushion. The cable anchored at a location toward the first end maybe anchored to the sled.

Technical benefits of the present invention include a crash cushionoperable to minimize the results of a collision between a vehicle and aroadside hazard. The crash cushion may include an energy absorbingassembly extending in a first direction from a first end of the crashcushion. The energy absorbing assembly may be moveable in the firstdirection when a vehicle impacts the first end. Multiple panel supportframes may be moveable in the first direction. Multiple panels may beattached to the panel support frames. The panels may diverge from thefirst direction as the panels extend from the first end. The panelsupport frames may be slidably coupled to anchors so as to resistrotation when a vehicle impacts the panels. The panel support frames maybe slidably coupled to anchors with at least one of the panel supportframes bearing on the energy absorbing assembly and may be coupled to anoutboard anchor. The panel support frames may be slidably coupled toanchors with at least one of the panel support frames bearing on theground and may be coupled to an outboard anchor. The panel supportframes may be slidably coupled to anchors with a hook located in achannel. The channel may be oriented in the first direction. The hookmay be coupled to one of the respective panel support frames or theanchor.

BRIEF DESCRIPTION OF THE DRAWINGS

A more complete understanding of the present invention may be acquiredby referring to the following description taken in conjunction with theaccompanying drawings in which like reference numbers indicate likefeatures and wherein:

FIG. 1 is a schematic drawing showing an energy absorbing systeminstalled adjacent to one end of a roadside hazard;

FIG. 2 is a schematic drawing showing a plan view with portions brokenaway of the roadside hazard and energy absorbing system of FIG. 1;

FIG. 3 is a schematic drawing showing an isometric view with portionsbroken away of a cutter plate and an energy absorbing assembly having aplurality of energy absorbing elements and supporting beamsincorporating teachings of the present invention;

FIG. 4 is a schematic drawing in section with portions broken away takenalong lines 4-4 of FIG. 3 showing the box beam type cross section of theenergy absorbing assembly;

FIG. 5 is a schematic drawing showing an isometric view with portionsbroken away of the energy absorbing assembly of FIG. 3 after the energyabsorbing elements have been cut or ripped while absorbing energy from avehicle impact;

FIG. 6 is a schematic drawing in section with portions broken awayshowing an energy absorbing assembly incorporating another embodiment ofthe present invention;

FIG. 7 is an exploded schematic drawing showing an isometric view withportions broken of still another embodiment in which the energyabsorbing assembly includes progressively thicker energy absorbingelements along the length of the associated energy absorbing assembly tostop an impacting automobile with a gradually increasing deceleration orstopping force applied to the impacting automobile;

FIG. 8 is a schematic drawing showing an isometric view with portionsbroken away of an energy absorbing element having a plurality of cutoutsto minimize damage to a light weight motor vehicle during impact with anenergy absorbing assembly;

FIG. 9A is a schematic drawing showing a plan view with portions brokenaway of another energy absorbing system incorporating teachings of thepresent invention installed adjacent to a roadside hazard;

FIG. 9B is a schematic drawing showing a plan view with portions brokenaway after a motor vehicle has collided with or impacted one end of theenergy absorbing system of FIG. 9A;

FIG. 9C is a schematic drawing showing a plan view of still anotherenergy absorbing system incorporating teachings of the present inventioninstalled adjacent to one end of a roadside hazard;

FIG. 10 is a more detailed schematic drawing showing an elevational viewwith portions broken away of the energy absorbing system of FIGS. 9A and9B;

FIG. 11 is a schematic drawing with portions broken away showing anisometric view of a sled assembly and other components at the end of theenergy absorbing system of FIG. 10 opposite from the roadside hazard;

FIG. 12 is a schematic drawing with portions broken away showing anisometric view of the sled assembly associated with the energy absorbingsystem of FIG. 10;

FIG. 13 is a schematic drawing in section with portions broken awayshowing one end of the sled assembly of FIG. 12 opposite from oncomingtraffic;

FIG. 14 is a schematic drawing with portions broken away showing anexploded isometric view of the sled assembly, cutter plate and rampassembly associated with the energy absorbing system of FIG. 10;

FIG. 15 is a schematic drawing showing an isometric view of overlappingpanels incorporating teachings of the present invention disposed alongone side of the energy absorbing system of FIG. 10;

FIG. 16 is a schematic drawing with portions broken away showing anisometric view of a panel support frame and attached panels associatedwith the energy absorbing system of FIG. 10;

FIG. 17A is a schematic drawing in section with portions broken awayshowing a first upstream panel and a second downstream panel slidablydisposed relative to each other in accordance with teachings of thepresent invention;

FIG. 17B is a schematic drawing showing an isometric view of a slotplate satisfactory for use in slidably attaching a panel incorporatingteaching of the present invention with a panel support frame;

FIG. 18 is a schematic drawing with portions broken away showing anexploded plan view of a cutter plate and energy absorbing elementssatisfactory for use with a energy absorbing system incorporatingteachings of the present invention;

FIG. 19A is a schematic drawing showing a plan view with portions brokenaway of an energy absorbing system incorporating teachings of thepresent invention installed adjacent to one or more roadside hazards;

FIG. 19B is a schematic drawing showing an enlarged plan view withportions broken away of the energy absorbing system of FIG. 19A;

FIG. 19C is a schematic drawing showing an isometric view of a bentplate which may be used to attach side panels to the energy absorbingsystem of FIG. 19A;

FIG. 20 is a schematic drawing in elevation with portions broken awayshowing a side view of the energy absorbing system of FIG. 19A;

FIG. 21 is a schematic drawing in section with portions broken awaytaken along lines 21-21 of FIG. 19A;

FIG. 22 is an enlarged schematic drawing in elevation with portionsbroken away showing a side view from FIG. 20 of one example of anoutboard anchor assembly;

FIG. 23 is a schematic drawing in elevation and in section with portionsbroken away taken along lines 23-23 of FIG. 19A showing one example of awing extension base plate, support post and brace;

FIG. 24 is a schematic drawing showing a plan view of an energyabsorbing system having a generally symmetrical configuration formed inaccordance with teachings of the present invention;

FIG. 25 is a schematic drawing in section taken along lines 25-25 ofFIG. 24;

FIG. 26 is a schematic drawing showing a plan view of a transitionbetween panels which may slide relative to each other and panels whichdo not slide relative to each other during a vehicle impact;

FIG. 27 is a schematic drawing in elevation with portions broken awaytaken along lines 27-27 of FIG. 26;

FIG. 28A is a schematic drawing showing a plan view with portions brokenaway of a cable coupled with one side of an energy absorbing system inaccordance with teachings of the present invention;

FIG. 28B is a schematic drawing in elevation with portions broken awayshowing the cable and associated coupling of FIG. 28A;

FIG. 29 is a schematic drawing in elevation showing one example of acoupling which may be used to connect a panel that slides with a panelthat does not slide;

FIG. 30 is a schematic drawing showing a plan view with portions brokenaway of still another energy absorbing system having a generallyasymmetrical configuration incorporating teachings of the presentinvention; and

FIG. 31 is a schematic drawing in section with portions broken awayshowing one example of a split panel support frame and an outboardanchor assembly incorporating teachings of the present invention.

DETAILED DESCRIPTION OF THE INVENTION

The present invention and its advantages are understood by referring toFIGS. 1-31 of the drawings, like numerals being used for like andcorresponding parts of the drawings.

Energy absorbing systems 120, 120 a and 420 incorporating teachings ofthe present invention may sometimes be referred to as crash cushions,crash barriers, or roadside protective systems. Energy absorbing systems120, 120 b and 420 may be used to minimize the results of a collisionbetween a motor vehicle (not expressly shown) and various types ofroadside hazards. Energy absorbing systems 120, 120 a and 420 and otherenergy absorbing systems incorporating teachings of the presentinvention may be used for both permanent installation and temporarywork-zone applications. Energy absorbing systems 120, 120 a and 420 andother energy absorbing systems incorporating teachings of the presentinvention meet or exceed NCHRP Report 350, Test Level 3 requirements.

The terms “longitudinal,” “longitudinally” and “linear” will generallybe used to describe the orientation and/or movement of componentsassociated with an energy absorbing system incorporating teachings ofthe present invention in a direction substantially parallel to thedirection vehicles (not expressly shown) travel on an adjacent roadway.The terms “lateral” and “laterally” will generally be used to describethe orientation and/or movement of components associated with an energyabsorbing system incorporating teachings of the present invention in adirection substantially normal to the direction vehicles travel on anadjacent roadway. Some components of energy absorbing systems 120, 120 aand 420 may be disposed at an angle (or flare) relative to the directionvehicles travel on an adjacent roadway.

The term “downstream” will generally be used to describe movement whichis substantially parallel with and in the same direction as movement ofa vehicle traveling an adjacent roadway. The term “upstream” willgenerally be used to describe movement which is substantially parallelwith but in the opposite direction as movement of a vehicle traveling onan adjacent roadway. The terms “upstream” and “downstream” may also beused to describe the position of one component relative to anothercomponent in an energy absorbing system incorporating teachings of thepresent invention.

The terms “separate” and “separating” will generally be used to describethe results of deforming an energy absorbing element using a cutterplate to cause failure of the energy absorbing element in tension inaccordance with teachings of the present invention. The terms “separate”and “separating” may also be used to describe the combined effects ofripping and tearing an energy absorbing element in accordance withteachings of the present invention.

The terms “gore” and “gore area” may be used to describe land where tworoadway diverge or converge. A gore is typically bounded on two sides bythe edges of the roadways which join at the point of divergence orconvergence. Traffic flow is generally in the same directions on bothsides of these roadways. A gore area often includes shoulders or markedpavement, if any, between the roadways. The third side or third boundaryof a gore area may sometimes be defined as approximately sixty (60)meters from the point of divergence or convergence.

The term “roadside hazard” may be used to describe permanent, fixedroadside hazards such as a large sign post, a bridge pillar or a centerpier of a bridge or overpass. Roadside hazards may also include atemporary work area disposed adjacent to a roadway or located betweentwo roadways. A temporary work area may include various types ofequipment and/or vehicles associated with road repair or construction.The term “roadside hazard” may also include a gore area or any otherstructure located adjacent to a roadway and presenting a hazard tooncoming traffic.

Various components of an energy absorbing system incorporating teachingsof the present invention may be formed from commercially availablestructural steel materials. Examples of such materials include steelstrips, steel plates, structural steel tubing, structural steel shapesand galvanized steel. Examples of structural steel shapes include Wshapes, HP shapes, beams, channels, tees, and angles. Structural steelangles may have legs with equal or unequal width. The American Instituteof Steel Construction publishes detailed information concerning varioustypes of commercially available steel structural materials satisfactoryfor use in fabricating energy absorbing systems incorporating teachingsof the present invention.

Roadside hazard 310 shown in FIGS. 1, 2, 9A, 9B, 10, and 198 may be aconcrete barrier extending along the edge or side of a roadway (notexpressly shown). Roadside hazard 310 may also be a concrete barrierextending along the median between two roadways. Roadside hazard 310 maybe a permanent installation or a temporary installation associated witha work area. Roadside hazard 310 may sometimes be described as a “fixed”barrier or “fixed” obstacle even though concrete barriers and otherobstacles adjacent to a roadway may from time to time be moved orremoved. An energy absorbing system incorporating teachings of thepresent invention is not limited to use with only concrete barriers.

Principal components of energy absorbing system 320 as shown in FIGS. 1,2, and 3 preferably include one or more energy absorbing assemblies 86,cutter plate or plates 106 and sled assembly 340. Cutter plate 106 mayalso be referred to as a “ripper” or as a “cutter blade.” For someapplications one end of each energy absorbing assembly 86 may beattached to roadside hazard 310 by respective struts 312. For someapplications energy absorbing assemblies 86 may also be fixed to theground in front of roadside hazard 310. A plurality of spacers or crossbraces 314 may be used to hold energy absorbing assemblies 86 alignedgenerally parallel with each other and extending longitudinally fromroadside hazard 310 toward oncoming traffic (not expressly shown).

Sled assembly 340 may be slidably coupled with the end of energyabsorbing assemblies 86 opposite from roadside hazard 310. Impact plate382 may be disposed on the end of sled assembly 340 facing oncomingtraffic. One or more of cutter plates 106 (not shown in FIGS. 1 and 2)are preferably provided as part of sled assembly 340. Respective cutterplates 106 are preferably slidably mounted relative to one end of eachenergy absorbing assembly 86 opposite from roadside hazard 310. When amotor vehicle (not expressly shown) contacts or collides with impactplate 382, sled assembly 340 will move longitudinally relative to energyabsorbing assemblies 86 and roadside hazard 310. As sled assembly 340moves toward roadside hazard 310, kinetic energy of the impacting motorvehicle may be dissipated by cutter plates 106 tearing or rippingassociated energy absorbing elements 100.

Energy absorbing assembly 86, as shown in FIGS. 3, 4, and 5 maysometimes be referred to as a “box beam.” Each energy absorbing assembly86 preferably includes a pair of supporting beams 90 disposedlongitudinally parallel with each other and are spaced from each other.Supporting beams 90 have a generally C-shaped or U-shaped cross section.The C-shaped cross section of each supporting beam 90 may be disposedfacing each other to define a generally rectangular cross section forenergy absorbing assembly 86. Supporting beams 90 may also be describedas channels. The C-shaped cross section of each support beam 90 may bedefined in part by web 92 and grips or flanges 94 and 96 extendingtherefrom. A plurality of matching holes 98 are preferably formed inboth grips 94 and 96 may be used to attach energy absorbing elements 100to energy absorbing assembly 86. Fasteners 103 preferably allow easyreplacement of energy absorbing elements 100 after collision of a motorvehicle with impact plate 382. A wide variety of fasteners may besatisfactorily used to attach energy absorbing elements 100 withsupporting beams 90.

For the embodiment shown in FIGS. 3, 4, and 5, a pair of energyabsorbing elements 100 may be attached to grips 94 on one side of energyabsorbing assembly 86. Another pair of energy absorbing elements 100 maybe attached to grips 96 on the opposite side of energy absorbingassembly 86. Spacers 104 are preferably disposed between each pair ofenergy absorbing elements 100 adjacent to respective grips 94 and 96. Aplurality of fasteners 103 extend through holes 98 in grips 94 and 96and associated energy absorbing elements 100. For some applications,energy absorbing elements 100 have a relatively uniform thickness. Forsome applications, it may be desirable to vary the thickness and/ornumber of energy absorbing elements extending along the length of anenergy absorbing assembly.

Energy absorbing elements 100 may be formed from various types of metalalloys. For some applications, mild steel may be preferred. The numberof energy absorbing elements 100 and their length and thickness may bevaried depending upon the intended application for the resulting energyabsorbing assembly. Increasing the number of energy absorbing elements,increasing their thickness, and/or increasing the length of energyabsorbing elements 100, will allow the resulting energy absorbingassembly to dissipate an increased amount of kinetic energy. Energyabsorbing elements 100 may also be referred to as rip plates or shearplates. Benefits of the present invention include the ability to varythe geometric configuration and number of energy absorbing elements 100and to select appropriate metal alloys depending upon the intendedapplication for the resulting energy absorbing assembly.

For the embodiment shown in FIG. 3, cutter plate 106 includes a pair ofbeveled cutting edges or ripping edges 107 and 109 disposed at first end101 of respective energy absorbing assembly 86. Cutting edges 107 and109 may also be described as rip blades. The thickness of cutter plates106 and gap 118 between supporting beams 90 are selected to allow cutterplate 106 to fit between grips 94 and 96 and adjacent supporting beams90.

Slots 102 are preferably formed in the end of each energy absorbingelement 100 adjacent to respective cutter plate 106. Cutting edges 107and 109 are preferably disposed at an acute angle relative to energyabsorbing elements 100. For the embodiment shown in FIG. 3, cuttingedges 107 and 109 may be hardened and formed at an angle ofapproximately forty-five degrees relative to associated energy absorbingelements 100. The configuration of cutting edges 107 and 109, includingtheir orientation relative to energy absorbing elements 100, ispreferably selected to cause the associated energy absorbing elements100 to fail in tension as they are stretched between respective grips 94and 96 of the associated support beams 90.

Energy absorbing elements 100 and other metal components of an energyabsorbing system incorporating teachings of the present invention arepreferably galvanized to insure that they retain their desired tensilestrength and are not affected by environmental conditions which maycause rust or corrosion during the life of the associated energyabsorbing system. Specific dimensions of cutting edges 107 and 109,along with their angular relationship relative to energy absorbingelements 100, may be varied depending upon the amount of kinetic energywhich will be dissipated by energy absorbing assembly 86.

When a motor vehicle collides with or contacts impact plate or impactfence 382, the force of the collision or impact is generally transmittedto energy absorbing assemblies 86 by cutter plate 106. As sled assembly340 slides longitudinally toward roadside hazard 310, kinetic energy ofan impacting vehicle may be dissipated through cutting or ripping ofenergy absorbing elements 100 by cutter plate 106 as shown, for example,in FIG. 5.

For relatively low speed impacts, such as between approximately fivemiles per hour and eighteen miles per hour or higher, one or morerelatively short lengths of energy absorbing elements 100 may beinstalled immediately adjacently to cutter plate 106. Thus, following alow speed impact only relatively short lengths of energy absorbingelements 100 will require replacement which substantially simplifiesrepair and maintenance of energy absorbing system 320.

As shown in FIG. 2, energy absorbing assemblies 86 are preferablysecured to each other by a plurality of cross braces 314. Cooperationbetween impact fence 382, cross braces 314 and energy absorbingassemblies 86 results in energy absorbing system 320 having a very rigidframe structure. As a result, energy absorbing system 320 is better ableto safely absorb impact from a motor vehicle that strikes impact fence382 either offset from the center of impact fence 382 or that strikesimpact fence 382 at an angle other than parallel with energy absorbingassemblies 86.

Energy absorbing assemblies 186 and 486 as shown in FIGS. 6 and 7 may besatisfactorily used with any energy absorbing systems incorporatingteachings of the present invention. Energy absorbing assembly 186includes a pair of supporting beams or channels 190 similar topreviously described supporting beams 90 for energy absorbing assembly86. Energy absorbing assembly 186 is shown with only two energyabsorbing elements or rip plates 152 disposed on opposite sides thereof.Channels 190 are spaced from each other to define cutting zone or gap154 therebetween.

Energy absorbing elements 152 may be attached to supporting beams 190using various types of fasteners including bolts 103 as previouslydescribed for energy absorbing assemblies 86. Mechanical fasteners 198 aand 198 b as shown in FIGS. 13 and 14 may also be used to attach energyabsorbing elements 152 with supporting beams 190. Alternatively, energyabsorbing elements 152 may be attached to supporting beams 190 usingother types of fasteners such as Huck bolts, rivets, by welding or byvarious adhesives. One requirement for attaching energy absorbingelements 152 with supporting beams 190 includes providing anappropriately sized cutting zone 154 between supporting beams 190 toaccommodate the associated cutter plate (not shown).

FIG. 7 is an exploded schematic drawing showing energy absorbingassembly 486. Some of the differences between energy absorbingassemblies 86 and energy absorbing assembly 486 include variations inthe length and thickness of the energy absorbing elements which arereplaceably secured to energy absorbing assembly 486. Energy absorbingassembly 486 may be formed using supporting beams 90 as previouslydescribed with respect to energy absorbing assembly 86.

For one application, supporting beams or C-channels 90 have an overalllength of approximately eleven feet with a web width of approximatelyfive inches and a flange height of approximately two inches. Multipleenergy absorbing elements or rip plates 402, 404, 406, 408, 410 and 412and multiple spacers 416 and 418 are preferably attached to C-channels90 by threaded fasteners. For the example shown in FIG. 7, the samenumber and configuration of energy absorbing elements 402, 404, 406 ofvarious lengths and thicknesses are secured on opposite sides ofC-channels 90. For one application, energy absorbing elements 402, 404,406, 408, 410, and 412 were formed from galvanized mild steel plates.The number of energy absorbing elements, their thickness and location onthe exterior of energy absorbing assembly 486 may be selected to providedesired deceleration characteristics for various sizes and types ofvehicles during both high speed and low speed impacts.

Spacers 416 and 418 may be provided between energy absorbing elements410 and 412 on both sides of energy absorbing assembly 486. One of thetechnical benefits of the present invention includes the ability to varythe number, size and location of energy absorbing elements on each sideof an energy absorbing assembly to provide desired decelerationcharacteristics.

Slot 102 is preferably formed in energy absorbing elements 402 and 404immediately adjacent to the first end of energy absorbing assembly 486to receive an associated cutter plate. For one application, slot 102 maybe formed along the centerline of energy absorbing elements 402 and 404with an opening of approximately one and one-half inches tapering to aradius of approximately one-half inch in width over a length ofapproximately six inches.

For some applications, energy absorbing elements 402 and 404 may bereplaceably secured with the respective supporting beams 90 by usingrelatively short mechanical fastener 422. Also, the length of energyabsorbing elements 402 and 404 is relatively short in comparison withother energy absorbing elements attached to and forming a part of energyabsorbing assembly 486. The use of relatively short mechanical fasteners422 and relatively short energy absorbing elements 402 and 404 allowsenergy absorbing assembly 486 to be quickly repaired and returned toservice after a relatively minor impact. Mechanical fasteners 424,preferably extend from one side of energy absorbing assembly 486 to theother side of energy absorbing assembly 486. Mechanical fasteners 422and 424 may be bolts or Hucks as previously described.

Energy absorbing elements 402, 404, 406, 408, 410 and 412 providedeceleration characteristics which may be tailored for specific vehicleweights and speeds. For example, during approximately the first few feetof travel, of an associated cutter plate through energy absorbingassembly 486, two stages of stopping force or deceleration appropriatefor a vehicle weighing approximately 820 kilograms are provided. Theremaining travel of a cutter plate through energy absorbing assembly 486provides stopping force that is appropriate for larger vehicles weighingapproximately 2,000 kilograms. Variations in the location, size,configuration and number of energy absorbing elements 402, 404, 406,408, 410 and 412 allows energy absorbing assembly 486 to provide safedeceleration of vehicles weighing between 820 kilograms and 2,000kilograms.

Energy absorbing element 200 as shown in FIG. 8 has been modified toreduce the initial effects of an impact between a moving vehicle and anenergy absorbing system particularly with respect to lightweightvehicles. Oval slots 204 reduce the energy required to initiate rippingor tearing of energy absorbing element 200 on initial impactparticularly with respect to a lightweight vehicle. Oval slots 204cooperate with each other to substantially minimize the initial impactor jolt experienced by a lightweight vehicle colliding with sledassembly 340.

For some applications, center line slot 202 at first end 201 of energyabsorbing element 200 may have a width of approximately three quartersof an inch and a length of approximately six inches. Slot 202 may beused to receive cutter plate 206 during installation and align cutterplate 206 with energy absorbing elements 200. A plurality of elongated,oval slots 204 are preferably formed along the center line of energyabsorbing element 200 extending from slot 202. For one application, ovalslots 204 have a length of approximately two and one half (2½) inchesand a width of approximately three quarters (¾) of an inch. The distancebetween the center line of adjacent oval slots 204 may be approximatelythree inches. The number of oval slots 204 and the dimensions of ovalslots 204 may be varied depending upon intended applications for anassociated energy absorbing assembly. For one application, energyabsorbing element 200 may have an overall length of forty-five (45)inches and a width of four and one half (4½) inches.

For some applications, energy absorbing element 200 is preferablydisposed immediately adjacently to respective cutter plate 106. Limitingthe overall length of energy absorbing element 200 to approximatelyforty-five (45) inches reduces the time and cost of returning anassociated energy absorbing system to service following a collision by alightweight vehicle or a slow speed vehicle with sled assembly 340, ifrepair is deemed appropriate. After a collision which did not requireabsorbing a substantial amount of energy, it may only be necessary toreplace energy absorbing elements 200 and not all of the other energyabsorbing elements attached to an associated energy absorbing assembly86.

Various types of mechanical fasteners may be satisfactorily used toreleasably attach energy absorbing elements 100, 200, and/or 402, 404,406, 408, 410 and 412 with associated support beams 90. For someapplications, a combination of long bolts and short bolts may besatisfactorily used. For other applications, the mechanical fastenersmay be blind threaded rivets and associated nuts. A wide variety ofblind rivets, bolts and other fasteners may be satisfactorily used withthe present invention. Examples of such fasteners are available fromHuck International, Inc., located at 6 Thomas, Irvine, Calif.92718-2585. Power tools satisfactory for installing such blind rivetsare also available from Huck International and other vendors.

Energy absorbing system 20 as shown in FIGS. 9A, 9B and 10 may beinstalled adjacent to one end of roadside hazard 310 facing oncomingtraffic. Portions of energy absorbing system 20 are also shown in FIGS.11-18. Energy absorbing system 20 a is also shown in FIG. 9C. Energyabsorbing systems 20 and 20 a may be formed from substantially the samecomponents. Energy absorbing systems 20 and 20 a may sometimes bedescribed as nongating, redirective crash cushions.

FIG. 9A is a schematic plan view showing energy absorbing system 20 inits first position, extending longitudinally from roadside hazard 310.Sled assembly 40 is slidably disposed at first end 21 of energyabsorbing system 20. Sled assembly 40 may sometimes be referred to as an“impact sled.” First end 21 of energy absorbing system 20 includingfirst end 41 of sled assembly 40 faces oncoming traffic. Second end 22of energy absorbing system 20 is preferably securely attached to the endof roadside hazard 310 facing oncoming traffic. Energy absorbing system20 is generally installed in its first position with first end 21longitudinally spaced from second end 22 as shown in FIG. 9A.

A plurality of panel support frames 60 a-60 e are spaced longitudinallyfrom each other and slidably disposed between first end 21 and secondend 22. Panel support frames 60 a-60 e may sometimes be referred to as“frame assemblies.” The number of panel support frames may be varieddepending upon the desired length of an associated energy absorbingsystem. Multiple panels 160 may be attached to sled assembly 40 andpanel support frames 60 a-60 e. Panels 160 may sometimes be referred toas “fenders” or “fender panels.”

When a vehicle impacts with first end 21 of energy absorbing system 20,sled assembly 40 will move longitudinally toward roadside hazard 310.Energy absorbing assemblies 186 (not expressly shown in FIGS. 9A and 9B)will absorb energy from the impacting vehicle during this movement.Panel support frames 60 a-60 e and associated panels 160 will alsoabsorb energy from a vehicle impacting first end 21. FIG. 9B is aschematic plan view which shows sled assembly 40 and panel supportframes 60 a-60 e and their associated panels 160 collapsed adjacently toeach other. Further longitudinal movement of sled assembly 40 towardroadside hazard 310 is prevented by panel support frames 60 a-60 e.

For purposes of explanation, the position of energy absorbing system 20as shown in FIG. 9B may be referred to as the “second” position. Duringmost vehicle collisions with end 21 of energy absorbing system 20, sledassembly 40 will generally move only a portion of the distance betweenthe first position as shown in FIG. 9A and the second position as shownin FIG. 9B.

Panel support frames 60 a-60 e, associated panels 160 and othercomponents of energy absorbing system 20 cooperate with each other toredirect vehicles striking either side of energy absorbing system 20back onto an associated roadway. Respective panels 160 are attached tosled assembly 40 and preferably extend over a portion of respectivepanels 160 attached to panel support frame 60 a. In a correspondingmanner, panels 160 attached to panel support frame 60 a preferablyextend over a corresponding portion of panels 160 attached to panelsupport frame 60 b. Various components of energy absorbing system 20provide substantial lateral support to panel support frames 60 a-60 eand panels 160.

First end 161 of each panel 160 is preferably securely attached to sledassembly 40 or panel support frame 60 a-60 d as appropriate. Each panel160 is also preferably slidably attached to one or more downstream panelsupport frames 60 a-60 e. Up stream panels 160 overlap down streampanels 160 to allow telescoping or nesting of respective panels 160 aspanel support frames 60 a-60 e slide toward each other. Subsets of panelsupport frames 60 a-60 e and panels 160 may be grouped together to forma one-bay group or a two-bay group.

For purposes of illustration, second end 162 of each upstream panel 160is shown in FIGS. 9A and 9B projecting a substantial distance laterallyat the overlap with the associated downstream panel 160. As discussedlater in more detail, panels 160 will preferably nest closely with eachother to minimize any lateral projection at second end 162 which mightsnag a vehicle during a reverse angle impact with either side of energyabsorbing system 20.

FIG. 9C is a schematic plan view showing energy absorbing system 20 a inits first position, extending longitudinally from roadside hazard 310.Energy absorbing system 20 a includes first end 21 facing oncomingtraffic and second end 22 securely attached to roadside hazard 310.Energy absorbing system 20 a also includes sled assembly 40, panelsupport frames 60 a-60 g and respective panels 160.

Panels 160 extending along both sides of energy absorbing systems 20 and20 a may have substantially the same configuration. However, the lengthof panels 160 may vary depending on whether the respective panel is a“one-bay panel” or a “two-bay panel.” For purposes of explanation, a“bay” is defined as the distance between two adjacent panels supportframes.

The length of panels 160 designated as “two-bay panels” is selected tospan the distance between three-panel support frames when energyabsorbing systems 20 and 20 a are in their first position. For example,first end 161 of a two-bay panel 160 is preferably securely attached toupstream panel support frame 60 a. Second end 162 of the two-bay panel160 is preferably slidably attached to downstream panel support frame 60c. Another panel support frame 60 b is slidably coupled with two-baypanels 160 intermediate first end 161 and second end 162.

When sled assembly 40 hits panel support frame 60 a which may in turncontact panel support frame 60 b and then 60 c, etc., the panel supportframes 60 a-60 g and attached panels 160 are accelerated toward roadsidehazard 310. The inertia of panel support frames 60 a-60 g and attachedpanels 160 contributes to the deceleration of an impacting vehicle. Ifthe panel support frame of a one-bay group is hit, the one-bay groupwill be coupled to its own associated panels 160 and, therefore, willhave relatively high inertia. To soften deceleration of an impactingvehicle, a two-bay group is preferably disposed downstream from eachone-bay group. When sled assembly 40, or one or more panel supportframes being pushed by sled assembly 40, contacts the first panelsupport frame of a two-bay group (e.g., panel support frame 60 d), theinertia is the same or slightly more than (because of the longer panels160) the inertia of a one-bay group. However, when the second panelsupport frame of the two-bay group (e.g., panel support frame 60 e) iscontacted, the second panel support frame 60 has a lower inertia becauseit is only slidably coupled to the associated panels 160. Therefore,deceleration is somewhat reduced.

Energy absorbing system 20 a has the following groups of bays:2-2-1-2-2, where “2” means two bays and “1” means one bay. Beginning atsled assembly 40 and moving toward roadside hazard 310, energy absorbingsystem 20 a has a two-bay group (counting sled assembly 40 as a bay inand of itself), another two-bay group, a one-bay group, followed by atwo-bay group and another two-bay group.

As shown in FIG. 10, nose cover 83 may be attached to sled assembly 40at first end 21 of energy absorbing system 20. Nose cover 83 may be agenerally rectangular sheet of flexible plastic type material. Oppositeedges of nose cover 83 are attached to corresponding opposite sides ofend 41 of sled assembly 40. Nose cover 83 preferably includes aplurality of chevron delineators 84 which are visible to oncomingtraffic approaching roadside hazard 310. Various types of reflectorsand/or warning signs may also be mounted on sled assembly 40 and alongeach side of energy absorbing system 20.

Energy absorbing system 20 preferably includes multiple energy absorbingassemblies 186 aligned in respective rows 188 and 189 (See FIG. 18)extending generally longitudinally from roadside hazard 310 and parallelwith each other. For some applications, each row 188 and 189 may containtwo or more energy absorbing assemblies 186. Energy absorbing assembly186 in row 188 may be spaced laterally from energy absorbing assembly186 in row 189.

For some applications, energy absorbing assemblies 186 may be securelyattached to concrete foundation 308 in front of roadside hazard 310.Each row 188 and 189 of energy absorbing assemblies 186 has a respectivefirst end 187 which corresponds generally with first end 21 of energyabsorbing system 20. First end 41 of sled assembly 40 is also preferablydisposed adjacent to first end 187 of rows 188 and 189 prior to avehicle impact.

Ramp assembly 30 may be provided at end 21 of energy absorbing system 20to prevent small vehicles or vehicles with low ground clearance fromdirectly impacting first end 187 of rows 188 and 189. If ramp assembly30 is not provided, a small vehicle or vehicle with low ground clearancemay contact either or both first ends 187 and experience severedeceleration with substantial damage to the vehicle and/or injury tooccupants in the vehicle.

Various types of ramps and other structures may be provided to ensurethat a vehicle impacting end 21 of energy absorbing 20 will properlyengage sled assembly 40 and not directly contact first ends 187 of rows188 and 189. Ramp assembly 30 may include a pair of ramps 32. Each ramp32 preferably includes leg 34 with tapered surface 36 extendingtherefrom. Connectors 38 extend from leg 34 opposite from taperedsurface 36. Connectors 38 allow each ramp 32 to be securely engaged withrespective energy absorbing assembly 186.

For some applications, leg 34 may have a height of approximately six andone-half inches. Other components associated with energy absorbingsystem 20 such as energy absorbing assemblies 186 and guide rails 208and 209 will preferably have a generally corresponding height. Limitingthe height of ramps 32 and energy absorbing assemblies 186 will allowsuch components to pass under a vehicle impacting with end 41 of sledassembly 40.

Tapered surfaces 36 may have a length of approximately thirteen andone-half inches. Tapered surfaces 36 may be formed by cutting astructural steel angle (not expressly shown) having nominal dimensionsof three inches by three inches by one-half inch thick into sectionswith appropriate lengths and angles. The sections of structural steelangle may be attached to respective legs 34 using welding techniquesand/or mechanical fasteners. Ramps 32 may also be referred to as “endshoes.”

For some applications, roadside hazard 310 and/or energy absorbingsystem 20 may be disposed on and attached to a suitable concrete orasphalt foundation. For the embodiment shown in FIGS. 10 and 13 concretefoundation 308 preferably extends both longitudinally and laterally fromroadside hazard 310. As shown in FIGS. 13 and 18 energy absorbingassemblies 186 are preferably disposed on and securely attached to aplurality of crossties 24. Each crosstie 24 may be secured to concretefoundation 308 using respective anchor bolts 26. Various types ofmechanical fasteners and anchors in addition to anchor bolts 26 may besatisfactorily used to secure crossties 24 with concrete foundation 308.The number of crossties and the number of anchors used with eachcrosstie may be varied as desired for each energy absorbing system.

Crossties 24 may be formed from structural steel strips having a nominalwidth of three inches and a nominal thickness of one half inch. Thelength of each crosstie 24 may be approximately twenty-two inches. Threeholes are preferably formed in each crosstie 24 to accommodate anchorbolts 26. During a vehicle collision with either side of energyabsorbing system 20, crossties 24 are placed in tension. The materialsused to form crossties 24 and their associated configuration areselected to allow crossties 24 to deform in response to tension fromsuch side impacts and to absorb energy from the impacting vehicle.

Energy absorbing assemblies 186 are similar to previously describedenergy absorbing assemblies 86. For example, see FIGS. 6 and 13. Forpurposes of describing embodiments shown in FIGS. 9A-18, supportingbeams 190 immediately adjacent to crossties 24 are designated 190 a. Therespective supporting beams 190 disposed immediately there above aredesignated 190 b. Supporting beams 190 a and 190 b have substantiallyidentical dimensions and configurations (See FIG. 13) includingrespective web 192 with grips or flanges 194 and 196 extendingtherefrom. Four crossties 24 may be attached to web 192 of supportingbeams 190 a opposite from respective flanges 194 and 196. As a result,the generally C-shaped cross section of each supporting beam 190 aextends away from respective crossties 24.

The number of crossties 24 attached to each supporting beam 190 a may bevaried depending upon the intended use of the resulting energy absorbingsystem. For energy absorbing system 20, two supporting beams 190 a arespaced laterally from each other and attached to four crossties 24.Conventional welding techniques and/or mechanical fasteners (notexpressly shown) may be used to attach supporting beams 190 a withcrossties 24.

A plurality of energy absorbing elements 152 are preferably attached torespective supporting beams 190 a and 190 b using mechanical fasteners198 a and 198 b. For some applications each energy absorbing element 152may have substantially the same configuration and dimensions. For otherapplications such as shown in FIG. 18 energy absorbing elements 152 a,152 b, 152 c, 152 d, 152 e and 152 f with varying lengths, widths, andthicknesses may be used to form energy absorbing assemblies 186.

A pair of guide rails or guide beams 208 and 209 are preferably attachedto and extend laterally from respective supporting beams 190 b. For someapplications, guide rails 208 and 209 may be formed from structuralsteel angles having legs of equal width such as three inches by threeinches and a thickness of approximately one-half of an inch. For otherapplications, a wide variety of guides may be used. The presentinvention is not limited to guide rails or guide beams 208 and 209.

Guide rails 208 and 209 each have first leg 211 and second leg 212 whichintersect each other at approximately a ninety-degree angle. A pluralityof holes (not expressly shown) is preferably formed along the length ofsecond leg 212 to allow attaching guide rails 208 and 209 withmechanical fasteners 198 b to respective supporting beams 190 b.Mechanical fasteners 198 b are preferably longer than mechanicalfasteners 198 a to accommodate guide rails 208 and 209 and longitudinalforce causing sled assembly 40 to move toward roadside hazard 310.

As shown in FIG. 10, the length of guide rails 208 and 209 is longerthan the length of the associated rows 188 and 189 of energy absorbingassemblies 186. When energy absorbing system 20 is in its secondposition as shown in FIG. 9B, panel support frames 60 a-60 e aredisposed immediately adjacently to each other which prevents furthermovement of sled assembly 40. Therefore, it is not necessary for rows188 and 189 of energy absorbing assemblies 186 to have the same lengthas guide rails 208 and 209.

Sled assembly 40 may have the general configuration of an open sidedbox. See FIG. 12. The materials used to form sled assembly 40 and theirconfiguration are preferably selected to allow sled assembly 40 toremain intact after impact by a high speed vehicle. First end 41 of sledassembly 40 corresponds generally with first end 21 of energy absorbingsystem 20. End 41 may also be referred to as the “upstream” end of sledassembly 40. End 47 of sled assembly 40 is disposed opposite from end41. End 47 may also be referred to as the “downstream” end of sledassembly 40. Sled assembly 40 also includes sides 48 and 49 which extendbetween ends 41 and 47. As shown in FIGS. 11 and 13, sides 48 and 49 ofsled assembly 40 are preferably covered by panels 160. For purposes ofillustration, panels 160 have been removed from side 48 in FIG. 12.

Sled assembly 40 may be further defined by corner posts 42, 43, 44 and45 which extend generally vertically from guide rails 208 and 209. Asshown in FIGS. 10-14, corner posts 42 and 43 may be formed fromstructural steel strips having a width of approximately four inches, athickness of approximately three quarters of an inch. Each corner post42 and 43 has a length of approximately thirty-two inches. Taperedsurface 46 is preferably formed on the end of each corner post 42 and 43immediately adjacent to the ground or concrete foundation 308. Thedimensions and configuration of tapered surfaces 46 is preferablyselected to minimize or eliminate contact between concrete foundation308 and respective ends of corner posts 42 and 43 that might preventsmooth, linear movement of sled assembly 40 along guide rails 208 and209 toward roadside hazard 310.

Corner posts 44 and 45 may be formed from structural steel angles havinglegs of equal width such as two and one half inches by two and one halfinches and a thickness of approximately three-eighths of an inch. Cornerposts 44 and 45 preferably have a length of approximately twenty-nineinches. Various configurations of braces and supports may be used torigidly attach corner post 42, 43, 44 and 45 with each other to providedesired structural strength for sled assembly 40.

Top brace 141 preferably extends laterally between corner posts 42 and43. Top brace 142 preferably extends laterally between corner posts 44and 45. A pair of top braces 148 and 149 extend longitudinally betweentop braces 141 and 142 along respective sides 48 and 49 of sled assembly40. Bottom brace 51 preferably extends laterally between corner post 42and corner post 43 immediately above guide rails 208 and 209. Anotherbottom brace 52 preferably extends laterally between corner post 44 andcorner post 45 immediately above guide rails 208 and 209.

End 41 of sled assembly 40 also includes braces 146 and 147 extendingdiagonally between respective corner posts 42 and 43 and bottom brace51. Corner posts 42 and 43, top brace 141, bottom brace 51 and braces146 and 147 cooperate with each other to provide a very rigid, strongstructure at first end 41 of sled assembly 40. End 47 of sled assembly40 includes diagonal braces 143, 144 and 145 along with diagonal braces146 and 147 to provide additional structural support for sled assembly40.

The dimensions of end 41 of sled assembly 40 which are defined in partby corner posts 42 and 43, top brace 141 and bottom brace 51 areselected to catch or gather an impacting vehicle. During a collisionbetween a motor vehicle and first end 21 of energy absorbing assembly20, kinetic energy from the colliding vehicle may be transferred fromfirst end 41 to other components of sled assembly 40. The dimensions andconfiguration of end 41 may also be selected to effectively transferkinetic energy even if a vehicle does not impact the center of first end41 or if a vehicle impacts end 41 at an angle other than parallel withthe longitudinal axis of energy absorbing system 20.

A pair of C-shaped channels 50 and 53 preferably extend diagonally fromtop brace 141 to bottom brace 52. Channels 50 and 53 are preferablyspaced laterally from each other and laterally from corner posts 42 and43 and corner posts 44 and 45. Guide assembly 54 is preferably attachedto the ends of channels 50 and 53 extending from bottom brace 52. Thelength of channels 50 and 53 is selected to ensure that guide assembly54 will contact web 192 of respective supporting beams 190 b.

Guide assembly 54 preferably includes plate 55. The end of channels 50and 53 extending from bottom brace 52 are attached to one side of plate55. A pair of diverters 58 and 59 are preferably attached to and extendgenerally vertically from the opposite side of plate 55. Diverters 58and 59 may be disposed at an angle relative to each other and the centerof guide assembly 54 to assist in maintaining sled assembly 40 properlypositioned between rows 188 and 189 of energy absorbing assemblies 186.Plate 55 may sometime be referred to as a guide shoe or skid.

Respective tabs 56 and 57 may be attached to the bottom end of cornerposts 44 and 45 adjacent to energy absorbing assemblies 186. Tabs 56 and57 project laterally inward from respective corner posts 44 and 45toward and under guide rails 208 and 209. Bottom brace 52 is preferablyspaced from tabs 56 and 57 such that legs 211 of guide rails 208 and 209may be respectively disposed between tabs 56 and 57 and bottom brace 52.As shown in FIG. 13, tabs 56 and 57 cooperate with bottom brace 52 tosecurely maintain sled assembly 40 on guide rails 208 and 209 while atthe same time allowing sled assembly 40 to slide along guide rails 208and 209 toward roadside hazard 310. Tabs 56 and 57 are particularlyhelpful in preventing undesired lateral rotation of sled assembly 40 inresponse to a side impact. The inertia of sled assembly 40 and thefriction associated with bottom brace 52 sliding over the top of guiderails 208 and 209 and the friction caused by contact between plate 55and the top of supporting beams 190 b will contribute to deceleration ofthe impacting vehicle.

Most impacts between a motor vehicle and end 41 of sled assembly 40 willgenerally occur at a location substantially above energy absorbingassemblies 186. As a result, vehicle impact with end 41 will generallyresult in applying a rotational moment to sled assembly 40 which forcesbottom brace 52 to bear down on the top of guide rails 208 and 209.

The dimensions of plate 55 and diverters 58 and 59 are selected to becompatible with web 192 of channels 190. During a collision between amotor vehicle and end 41 of sled assembly 40, force from the vehicle istransferred from top brace 141 through channels 50 and 53 to bottombrace 52 and guide assembly 54. As a result, plate 55 will apply forceto supporting beams 190 b to maintain the desired orientation of sledassembly 40 relative to energy absorbing assemblies 186.

As shown in FIGS. 11, 12 and 14 connectors 214 and 216 may be attachedto bottom brace 51 opposite from cross braces 145 and 146. Connectors214 and 216 are spaced laterally from each other to receive connector220 which is attached to and extends from cutter plate 206. Connectors222 and 224 are also preferably attached to corner post 42 and extendlaterally therefrom. Corresponding connectors 222 and 224 are alsoattached to corner post 43 and extend laterally therefrom. Connectors222 are spaced from respective connectors 224 a distance correspondinggenerally with the thickness of cutter plate 206. As shown in FIG. 14, aplurality of holes may be provided in connectors 214, 216, 220, 222, 224and cutter plate 206 to allow mechanical fasteners to securely attachcutter plate 206 with sled assembly 40 adjacent to energy absorbingassemblies 186.

As shown in FIGS. 12, 14 and 18 cutter plate 206 preferably includes twosets of beveled cutting edges or ripping edges 107 and 109. Sledassembly 40 may be slidably disposed on guide rails 208 and 209 withcutting edges 107 and 109 aligned with first end 187 of energy absorbingassemblies 186. The thickness of cutter plate 206 and the gap or cuttingzone 154 between supporting beams 190 a and 190 b are selected to allowcutter plate 206 to fit between flanges 194 and 196 of supporting beams190 a and 190 b. Cutter plate 206 may be located within slots 102 ofenergy absorbing assemblies 186.

As shown in FIG. 14, cutter plate 206 preferably includes respectiveguide plates 268. A respective guide plate 268 may be provided on eachside of cutter plate 206 for each supporting beam 190. The width of eachguide plate 268 is selected to be compatible with the width of therespective supporting beam 190. The combined thickness of each cutterplate 206 along with respective guide plates 268 is selected to becompatible with gap or cutting zone 154 formed between respectivesupport beams 190. The thickness of cutting plate 206 is selected tocorrespond generally with the dimensions of gap 154. Each guide plate268 is preferably disposed within the generally C-shaped cross sectiondefined by web 192 and flanges 194 and 196 of the associated supportbeams 190. For some applications, gap or cutting zone 154 betweensupporting beams 190 a and 190 b may be approximately one inch (ortwenty-five millimeters) and the thickness of cutter plates 206 may beapproximately one half inch.

During a collision with end 21 of energy absorbing system 20, a vehiclewill experience a deceleration spike as momentum is transferred from thevehicle to sled assembly 40 which results in sled assembly 40 and thevehicle moving in unison with each other. The amount of deceleration dueto the momentum transfer is a function of the weight of sled assembly40, along with the weight and initial speed of the vehicle. As sledassembly 40 slides longitudinally toward roadside hazard 310, guideassembly 54 will contact respective supporting beams 190 a and 190 b tomaintain the desired alignment between sled assembly 40 and energyabsorbing assemblies 186 and cutter plates 206. Sled assembly 40maintains cutter blade 206 in alignment with cutting zone 154.

As sled assembly 40 continues sliding toward roadside hazard 310, cutterplate 206 will engage and separate energy absorbing elements 152 of therespective energy absorbing assemblies 186. When sled assembly 40 isimpacted by a vehicle, cutter plate 206 is pushed into the edge of eachenergy absorbing element 152. Beveled edges 107 and 109 of cutter plate206 engage respective energy absorbing elements 152. Cutter plate 206may be formed from various steel alloys. Beveled edges 107 and 109 arepreferably hardened to provide desired cutting and/or ripping of energyabsorbing elements 152.

The center portion of each energy absorbing element 152 may be forcedinwardly between respective supporting beams 190, while the top andbottom portions of each energy absorbing element 152 remains fixed torespective supporting beams 190 by bolts 198 a and 198 b. The centerportion of each energy absorbing element 152 continues to be stretchedor deformed by cutter plate 206 until respective energy absorbingelement 152 typically fails in tension. This creates a separation ineach energy absorbing element 152 which propagates along the length ofrespective energy absorbing elements 152 as sled assembly 40 continuesto be push cutter plate 206 therethrough.

The separation of energy absorbing elements 152 will stop when kineticenergy from the impacting vehicle has been absorbed. After the passageof cutter plate 206, one or more energy absorbing elements 152 will beseparated into upper and lower parts (See FIG. 5), which upper and lowerparts are separated by a gap.

Cutter plate 206, when viewed from associated energy absorbing elements152, has the configuration of a deep, strong beam. Cutter plate 206 issecured to sled assembly 40 at both ends and in the center and istherefore rigid. Thus, when cutter plate 206 engages energy absorbingelements 152, the energy absorbing elements 152 fails while cutter plate206 does not.

As previously noted, the thickness and number of energy absorbingelements 152 may be varied to safely absorb the kinetic energy from awide range of vehicle types, sizes and/or speeds of impact. Therotational moment which is generally applied to end 41 of sled assembly40 will also increase frictional forces between cutter plate 206 andportions of energy absorbing element 152 which have been sheared orripped.

For many applications, energy absorbing elements disposed immediatelyadjacently to sled assembly 40 will typically be relatively thin or“soft” to decelerate relatively small, slow-moving vehicles. The lengthof respective rows 188 and 189 associated with energy absorbing systems20, 120, 120 a, and 420 are preferably selected to be long enough toprovide multiple stages for satisfactory deceleration of large,high-speed vehicles after sled assembly 40 has moved through the frontportion with “relatively soft” energy absorbing elements. Generally,energy absorbing elements installed in the middle portion of rows 188and 189 and immediately adjacent to the end of each row will berelatively “hard” as compared to energy absorbing elements installedadjacent to first end 21.

When a vehicle initially impacts first end 41 of sled assembly 40 facingoncoming traffic, any occupants who are not wearing a seat belt or otherrestraining device will be catapulted forward from their seat. Properlyrestrained occupants will generally decelerate with the vehicle. Duringthe short time period and distance sled assembly 40 travels along guiderails 208 and 209, an unrestrained occupant may be airborne inside thevehicle. Deceleration forces applied to the impacting vehicle duringthis same time period may be quite large. However, just prior to anunrestrained occupant contacting interior portions of the vehicle, suchas the windshield (not expressly shown), deceleration forces applied tothe vehicle will generally be reduced to lower levels to minimizepossible injury to the unrestrained occupant.

For the embodiment as shown in FIG. 9A, end 47 of sled assembly 40 willcontact panel support frame 60 a which will, in turn, contact panelsupport frame 60 b and any other panel support frames disposeddownstream from sled assembly 40. Movement of sled assembly 40 towardroadside hazard 310 results in telescoping of panel support frames 60a-60 e and their associated panels 160 with respect to each other. Theinertia of panel support frames and their associated panels 160 willfurther decelerate an impacting vehicle as sled assembly 40 moveslongitudinally from first end 21 toward second end 22 of energyabsorbing system 20. The telescoping or sliding of panels 160 againstone another produces additional friction forces which also contribute todeceleration of the vehicle. Movement of panel support frames 60 a-60 ealong guide rails 208 and 209 also produces additional frictional forcesto even further decelerate the vehicle.

As previously discussed with respect to FIGS. 9A and 9B, panel supportframes 60 a-60 e and associated panels 160 will redirect vehiclesstriking either side of energy absorbing system 20 back onto theassociated roadway. Each panel 160 preferably has a generally elongatedrectangular configuration defined in part by first end or upstream end161 and second end or downstream end 162. (See FIGS. 9A, 10 and 15.)Each panel 160 preferably includes first edge 181 and second edge 182which extend longitudinally between first end 161 and second end 162.(See FIGS. 10 and 15.) For some applications panels 160 may be formedfrom standard ten (10) gauge W beam guardrail sections having a lengthof approximately thirty-four and three-fourth inches for “one-baypanels” and five feet two inches for “two-bay panels.” Each panel 160preferably has approximately the same width of twelve and one-fourthinches.

As shown in FIGS. 10 and 15, respective slot 164 is preferably formed ineach panel 160 intermediate ends 161 and 162. Slot 164 is preferablyaligned with and extends along the longitudinal center line (notexpressly shown) of each panel 160. The length of slot 164 is less thanthe length of the associated panel 160. A respective slot plate 170 isslidably disposed in each slot 164.

Metal strap 166 may be welded to first end 161 of each panel 160 alongedges 181 and 182 and the middle. See FIG. 16. For some applicationsmetal strap 166 may have a length of approximately twelve and one-fourthinches and a width of approximately two and one-half inches. The lengthof each metal strap 166 is preferable equal to the width of therespective panel 160 between respective longitudinal edges 181 and 182.

Mechanical fasteners 167, 168, and 169 may be used to attach each metalstrap 166 with its associated corner post 68 or 69. Mechanical fasteners167 and 169 are substantially identical. Metal straps 166 provide morecontact points for mounting end 161 of panels 160 to respective panelsupport frames 60 a-60 f.

Recesses 184 are preferably formed in each panel 160 at the junctionbetween second end 162 and respective longitudinal edges 181 and 182.(See FIG. 15) Recesses 184 allow panels 160 to fit with each other in atight overlapping arrangement when energy absorbing system 20 is in itsfirst position. As a result, recesses 184 minimize the possibility of avehicle snagging the sides of energy absorbing system 20 during a“reverse angle” collision or impact.

Panel support frames 60 a-60 e may have substantially the samedimensions and configuration. Therefore, only panel support frame 60 ewill be described in detail. See FIG. 16. For some applications panelsupport frame 60 e has a generally rectangular configuration defined inpart by first post 68 disposed adjacent to guide rail 208 and secondpost 69 disposed adjacent to guide rail 209. Top brace 61 extendslaterally between first post 68 and second post 69. Bottom brace 62extends laterally between first post 68 and second post 69. The lengthof posts 68 and 69 and the location of bottom brace 62 are selected suchthat when panel support frame 60 e is disposed on guide rails 208 and209, bottom brace 62 will contact guide rails 208 and 209 but posts 68and 69 will not contact concrete foundation 308.

A plurality of cross braces 63, 64, 65, 70 and 71 may be disposedbetween posts 68 and 69, top brace 61 and bottom brace 62 to provide arigid structure. For some applications cross braces 63, 64, 65, 70 and71 and/or posts 68 and 69 may be formed from relatively heavy structuralsteel components. Also, cross brace 65 may be installed at a lowerposition on posts 68 and 69. The weight of support frames 60 a-60 e andthe location of the associated cross braces may be varied to providedesired strength during a side impact with energy absorbing system 20.

Tab 66 is attached to the end of post 69 adjacent to concrete foundation308 and extends laterally toward energy absorbing assemblies 186. Tab 67is attached to the end of post 68 adjacent to concrete assembly 308 andextends laterally toward energy absorbing assemblies 186. Tabs 66 and 67cooperate with bottom brace 62 to maintain panel supporting frame 60 eengaged with guide rails 208 and 209 during a side impact with energyabsorbing system 20.

Impact from a vehicle colliding with either side of energy absorbingassembly 20 will be transferred from panels 160 to panel support frames60 a-60 g. The force of the lateral impact will then be transferred frompanel support frames 60 a-60 g to the associated guide rails 208 and/or209 to energy absorbing assemblies 186 through crossties 24 andmechanical fasteners 26 to concrete foundation 308. Crossties 24,mechanical fasteners 26, energy absorbing assemblies 186, guide rails208 and 209 along with panel support frames 60 a-60 g provides lateralsupport during a side impact with energy absorbing system 20.

For purposes of explanation, panels 160 shown in FIG. 15 have beendesignated 160 a, 160 b, 160 c, 160 d, 160 e and 160 f. Further, thelongitudinal edges of panels 160 a-160 d are identified as longitudinaledges 181 a-181 d and 182 a-182 d, and the longitudinal edges of panel160 f are identified as longitudinal edges 181 f and 182 f. Also, forpanels 160 a, 160 b, and 160 d, ends 161 and 162 are identified as ends161 a and 162 a, ends 161 b and 162 b, and ends 161 d and 162 d,respectively. Likewise, for panel 160 c, the upstream end is identifiedas end 161 c; and for panel 160 e, the downstream end is identified asend 162 e. As shown in FIGS. 15 and 17A, respective metal straps 166 maybe attached to first end 161 a and first end 161 d to post 68 of panelsupport frame 60 c. In a similar manner, respective metal straps 166 areprovided to securely attach first end 161 b and 161 e to corner post 68of panel support frame 60 d. As shown in FIGS. 17A and 17B, bolt 168extends through hole 172 in respective slot plate 170 and acorresponding hole (not expressly shown) in panel 160 b.

As shown in FIG. 17, slot plate 170 preferably includes hole 172extending therethrough. A pair of fingers 174 and 176 extend laterallyfrom one side of slot plate 170. Fingers 174 and 176 are sized to bereceived within slot 164 of the associated panel 160. Mechanicalfastener 168 is preferably longer than mechanical fasteners 167 and 169to accommodate slot plate 170. Each slot plate 170 and bolt 168cooperate with each other to securely anchor end 161 of an inner panel160 with the associate post 68 or 69 while allowing an outer panel 160to slide longitudinally relative to the associated post 68 or 69. Seeinner panel 160 b and outer panel 160 a in FIG. 17A.

A portion of each bolt 168 along with associated fingers 174 and 176 ofslot plate 170 may be slidably disposed in respective slot 164 of eachpanel 160. During a vehicle impact with end 21 of energy absorbingassembly 20, panel support frame 60 c with first end 161 a of panel 160a will move longitudinally toward roadside hazard 310. The engagement ofthe associated slot plate 170 within longitudinal slot 164 will allowpanel 160 a to slide longitudinally relative to panel 160 b until panelsupport frame 60 c contacts panel support frame 60 d. When this contactoccurs, panel support frame 60 d and associated panels 160 will movewith panel support frame 60 c and its associated panels 160 towardroadside hazard 160.

Relative “softness” or “hardness” of an energy absorbing system may bedetermined by the number and characteristics of energy absorbingelements 152, the location of energy absorbing elements 152, and thelocation and inertia associated with panel support frames 60 a-60 g andtheir associated panels 160. For example, energy absorbing element 200shown in FIG. 8 may be modified to be relatively hard by reducing thenumber and/or size of oval slot 204. In the same manner, energyabsorbing element 200 may be made relatively soft by increasing thenumber and/or size of oval slot 204. Increasing the thickness of energyabsorbing elements 152 will increase the amount of force required topush cutter plate 206 therethrough and thus, produces a harder portionin the associated energy absorbing system. Energy absorbing assembly 486as previously described in FIG. 7 shows various techniques forincreasing the hardness of an energy absorbing system.

Energy absorbing system 20 as shown in FIG. 18 preferably includesenergy absorbing elements 152 a, 152 b, 152 c, 152 d, 152 e and 152 f.Energy absorbing elements 152 a and 152 b are preferably formed fromrelatively thin sixteen gauge construction steel strips having a nominalwidth of four and one half inches. Energy absorbing element 152 apreferably has a nominal length of approximately fifty-four inches.Energy absorbing element 152 b preferably has a nominal length ofapproximately sixty inches. Energy absorbing elements 152 c and 152 dare preferably formed from structural steel strips having a nominalwidth of four and one half inches and thickness of three-sixteenths ofan inch. Energy absorbing element 152 c preferably has a nominal lengthof approximately seventy-six inches. Energy absorbing element 152 dpreferably has a nominal length of approximately seventy inches. Energyabsorbing elements 152 e are preferably formed from the same type ofmaterial. Energy absorbing elements 152 f are preferably formed fromstructural steel strips having a width of approximately four andone-half inches and a length of approximately ninety-two inches. Eachenergy absorbing element 152 f preferably has a thickness correspondingwith ten gauge construction steel strips.

Various components and features of energy absorbing systems 320 and 20such as energy absorbing assemblies 86, 186 and 486 and energy absorbingelements 100, 152, 200, 402, 404, 406, 408, 410 and 412 may beincorporated into energy absorbing systems 120, 120 a and 420 asdesired. Energy absorbing systems 120, 120 a and 420 may dissipatekinetic energy by ripping or tearing respective energy absorbingelements. However, other types of energy absorbing assemblies may besatisfactorily used with an energy absorbing system having flared sidesand/or wing extensions formed in accordance with teachings of thepresent invention.

Energy absorbing system 120, shown in FIGS. 19A-23 incorporatingteachings of the present invention, may be installed adjacent to arelatively wide or large roadside hazard facing oncoming traffic. Energyabsorbing system 120 a incorporating a further embodiment of the presentinvention is shown in FIGS. 24 and 25. Various components which may beused with energy absorbing systems 120 and 120 a are shown in FIGS.26-29. Energy absorbing system 420 incorporating still anotherembodiment of the present invention is shown in FIGS. 30 and 31. Energyabsorbing systems 120, 120 a and 420 may sometimes be described as“non-gating, redirective crash cushions.” Energy absorbing systems 120,120 a and 420 may also be described as “flared” systems because the endof each system disposed adjacent to a roadside hazard is typicallysubstantially wider than the end of the respective system facingoncoming traffic.

Energy absorbing systems 120, 120 a and 420 may include multiple energyabsorbing assemblies 186 aligned in respective rows 188 and 189extending generally longitudinally from first end 121 to a positionintermediate an associated roadside hazard (not expressly shown). Rows188 and 189 may also be aligned generally parallel with each other. Rows188 and 189 and/or energy absorbing assemblies 186 may sometimes bereferred to as a “guidance track” for sled assembly 40 and panel supportframes 60 a-60 g (See FIGS. 19A and 24) or split panel support frames460 a-460 i (See FIGS. 30 and 31). Some features associated with energyabsorbing systems 120, 120 a and 420 may be described with respect tolongitudinal center line 130 disposed between rows 188 and 189.

An energy absorbing system incorporating teachings of the presentinvention may have energy absorbing assemblies arranged in variousconfigurations. For some applications, only a single row of energyabsorbing assemblies may be installed adjacent to a roadside hazard. Forother applications, three or more rows of energy absorbing assembliesmay be installed. Also, each row may only have one energy absorbingassembly or multiple energy absorbing assemblies. The present inventionallows modifying an energy absorbing system to minimize possible injuryto both restrained and unrestrained occupants in a wide variety ofvehicles traveling at various speeds.

In fact, other types of energy absorbing assemblies can be utilized withsystems 120, 120 a and 420 of FIGS. 19A-31. The energy absorbingassemblies can utilize crushing, extruding, bursting, splitting, etc.

Energy absorbing assemblies 186 are preferably disposed on and securelyattached to a plurality of crossties 24. For some applications, energyabsorbing systems 120, 120 a and/or 420 may be installed using a totalof eight crossties 24 with four anchor bolts 26 per crosstie. Two anchorbolts 26 may be installed adjacent to each end of each crosstie 24. Thenumber and location of crossties 24 and anchor bolts 26 may be varied toprovide sufficient mechanical strength to resist large forces which maybe generated when a vehicle impacts with one side of the associatedenergy absorbing system. For example, a relatively strong structuralbase and foundation may be required to satisfactorily redirect a vehicleimpacting at an angle of approximately twenty degrees (20°) with aportion of an energy absorbing system having a flare of approximatelyseven degrees (7°).

A pair of guide rails or guide beams 208 and 209 are preferably attachedto and extend laterally from respective energy absorbing assemblies 186.Sled assembly 40 may be slidably disposed on guide rails 208 and 209.Panel support frames 60 a-60 g of energy absorbing systems 120 and 120 aand split panel support frames 460 a-460 i of energy absorbing system 42may also be slidably disposed on guide rails 208 and 209. The length ofguide rails 208 and 209 is preferably longer than the length ofassociated rows 188 and 189 of energy absorbing assemblies 186. Whenenergy absorbing systems 120 and 120 a are in their respective secondposition (not expressly shown), sled assembly 40 and panel supportframes 60 a-60 g may be disposed adjacent to each other at the end ofrows 188 and 189 opposite from first end 121. When energy absorbingsystem 420 is in its second position (not expressly shown), sledassembly 40 and split panel support frames 460 a-460 i may be disposedadjacent to each other at the end of rows 188 and 189 opposite fromfirst end 121.

FIG. 19A is a schematic drawing showing a plan view of energy absorbingsystem 120, extending longitudinally from a roadside hazard (notexpressly shown) which may include concrete barrier 310. Energyabsorbing system 120 includes first end 121 facing oncoming traffic andsecond end 122 disposed adjacent to the roadside hazard. Energyabsorbing system 120 also includes first side 131 and second side 132which are spaced from each other and extend generally longitudinallybetween first end 121 and second end 122. For this embodiment first side131 and second side 132 may be described as having a generallyasymmetrical configuration relative to center line 130.

When energy absorbing system 120 is in its first position, sled assembly40 may be slidably disposed at first end 121 facing oncoming traffic.Second end 122 of energy absorbing system 120 may be disposed adjacentto a relatively large, wide roadside hazard (not expressly shown). Forthe embodiment as shown in FIG. 19A, second end 122 a of first side 131may be attached with concrete barrier 310. Second end 122 b of secondside 132 may be attached with a similar concrete barrier or withportions of a conventional guardrail system (not expressly shown).

Multiple panels 160 may be attached to sled assembly 40 and panelsupport frames 60 a-60 g to form portions of first side 131 and secondside 132. For the embodiment shown in FIG. 19A, first side 131 andsecond side 132 extend generally parallel with each other from first end121 along at least a portion of centerline 130. Second side 132 ofenergy absorbing system 120 may be described as “flared” because secondportion 132 b of second side 132 is disposed at an angle relative tolongitudinal center line 130, associated rows 188 and 189 and guiderails 208 and 209. The second portion 132 b of the second side divergesfrom the center line 130 as the side extends toward the second end 122.First portion 132 a of second side 132 disposed between first end 121and support frame assembly 60 c is preferably spaced from and alignedgenerally parallel with corresponding portions of first side 131. Forsome applications the distance between first end 121 and the location atwhich second portion 132 b of second side 132 flares or extends at anangle from associated guide rails 208 and 209 may be approximately onehundred fourteen inches (114″). Providing modular base units of onehundred fourteen inches (114″) also reduces the amount of testingrequired for the associated energy absorbing system to meet NCHRP Report350 requirements.

Technical benefits of the present invention include providing modularbase units which may be preassembled prior to delivery at a roadsidelocation. For some applications a modular base unit may include rows 188and 189, sled assembly 40, panel support frames 60 a-60 g with panels160 installed along side 131 and panels 160 installed alongapproximately one hundred fourteen inches (114″) of side 132. The use ofa modular base unit may minimize repair time at a roadway location andallow for more efficient, cost effective repair of a damaged modularbase unit at an off site repair facility.

FIG. 19B is an enlarged schematic drawing showing a plan view of therelationship between first portion 132 a and second portion 132 b ofsecond side 132. For the embodiment represented by energy absorbingsystem 120 second portion 132 b may be disposed at an angle ofapproximately seven degrees (7°) relative to first portion 132 a. Bentplates or joint plates 74 may be used to couple panel support frame 60 cand frame extensions 80 d-80 g with respective panels 160. Bent plate orjoint plate 74 may be installed on the downstream side of panel supportframe 60 c. Respective joint plates or bent plates 74 may be installedon the upstream side of associated frame extensions 80 d-80 g. Bentplates 74 may include angle 76 having a value of approximately sevendegrees (7°) which corresponds generally with the angle formed betweenfirst portion 132 a and second portion 132 b of second side 132. SeeFIG. 19C.

The joint plates 74 are used in conjunction with the straps 166 of FIGS.16 and 17 a. The straps 166 are used to couple the panels to the panelsupport frames 60 a, 60 b and to the sled 40, wherein the panels extendgenerally perpendicular to the panel support frames. Where the panelsare nonperpendicular to the panel support frames, or to other types ofsupports, the joint plates 74 are used to couple the panels to thecorresponding supports. Angle 76 of joint plate 74 (see FIG. 19C)generally corresponds to the angle of the panels with respect to theassociated supports. Joint plates 74 are not needed to couple the panelsto the wing extension panel support frames 360 h-360 m, as the panelsgenerally extend perpendicular to the panel support frames. Each jointplate 74 includes a first portion 74 a and a second portion 74 b. Thefirst and second portions 74 a, 74 b have openings therein for bolts.

FIG. 19B illustrates the use of the joint plates 74. One joint plate 74is coupled to the panel support frame 60 d (more specifically to theextension 80 d). Specifically, the first portion 74 a of the plate 74 isbolted to the extension 80 d and the second portion 74 b, which extendstoward the first end 121 and inward toward the center line 130, isbolted to a strap 166 that is connected to the panel 160 dd. The end ofthe panel 160 dd that is toward the first end 121 is fixedly coupled tothe plate. The end of the panel 160 cc that is toward the second end 122is slidingly coupled to the joint plate 74, in the same manner asdiscussed above with reference to FIG. 15. Another joint plate 74 iscoupled to the panel support frame 60 c. Specifically, the first portion74 a is bolted to the panel support frame 60 c and the second portion 74b, which extends toward the second end 122 and away from the center line130, is bolted to a strap 166 (not expressly shown in FIG. 19B) on thepanel 160 cc. The adjacent end of the panel 160 bb is slidingly coupledto the panel support frame 60 c, as previously discussed with referenceto FIG. 15.

Energy absorbing system 120 may also be described as “right sideflared”. For some applications, first side 131 may be flared relative tocenter line 130 (not expressly shown) and second side 132 may extendgenerally parallel with center line 130 (not expressly shown). Theresulting energy absorbing system may be described as “left side flared”(not expressly shown). The present invention allows an energy absorbingsystem to be designed and installed based on associated geometry of eachroadside hazard and installation topography. For example, one side of anenergy absorbing system formed in accordance with teachings of thepresent invention may be flared near an exit ramp (not expressly shown)at an angle corresponding with an angle formed between the main line oftraffic flow and the exit ramp. An energy absorbing system having asingle side flare allows an associated energy absorbing assembly toremain substantially parallel with the main direction of traffic flowwhile still providing substantially continuous crash protection forvehicles exiting from the main line of traffic flow onto an exit ramp.

Starting with panel support frame 60 d, respective frame extensions 80d-80 g may be disposed adjacent to associated panel support frames 60d-60 g. Frame extensions 80 d-80 g may slide longitudinally along withrespective panel support frames 60 d-60 g. Respective outboard anchorassemblies 110 e-110 g are preferably secured adjacent to row 189 andspaced therefrom to support each frame extension 80 e-80 g at an anglecorresponding generally with the angle of second portion 132 b of secondside 132. Frame extensions 80 e-80 g are preferably slidably disposed ontheir associated outboard anchor assembly 110 e-110 g. The number offrame extensions and the number of outboard anchor assemblies may bevaried depending upon characteristics of each roadside hazard and angleor angles associated with sides 131 and 132.

For the embodiment represented by energy absorbing system 120 frameextensions 80 d-80 f may have similar overall configurations. Frameextensions 80 d-80 g may be described as having generally rectangularcross sections with one or more corner posts 68 a, 69 a coupled togetherby one or more cross braces 82. However, dimensions associated with eachframe extension 80 d-80 f may be varied to accommodate the flare orangle formed by second portion 132 b of second side 132. Frame extension80 f is shown in more detail in FIG. 21. One of the corner ports 68 a ofthe frame extension may be fastened to one of the corner posts 68 of thepanel support frame 60.

As shown in FIG. 19A, the width of frame extension 80 d is generallysmaller than the width of frame extensions 80 e, 80 f and 80 g. As thewidth of frame extensions 80 increases, respective outboard anchorassemblies 110 e-110 g may be located at an appropriate distance fromguide rail 209 to provide desired mechanical support for frameextensions 80 e-80 g and associated panels 160. Since the width of frameextension 80 d is less than the width of the other frame extension 80e-80 g, an outboard anchor assembly 110 may not be required for frameextension 80 d at some roadside installations.

Various features of outboard anchor assemblies 110 e-110 g are shown inFIGS. 19A, 20, 21, 22 and 25. Each outboard anchor assembly 110 e-110 gpreferably includes respective base plate 112, four anchor bolts 26 andguide plate 114. Webs or supporting members 116, 116 a may be used tomount guide plate 114 with respective base plate 112. Respective hooks117 may be attached with the exterior of each frame extension 80 e, 80 fand 80 g adjacent to guide plates 114. The dimensions of each hook 117are preferably selected to allow respective frame extensions 80 e-80 gto slide longitudinally relative to the associated guide plate 114. Eachhook 117 cooperates with its associated guide plate 114 to preventrotation of associated frame extension 80 e-80 g during a vehicle impactwith side 132. Web 116 a is positioned on the opposite side of the web116 from the hook 117. Thus, the outboard anchor assembly forms achannel for receiving the hook 117, which channel is generally parallelto the center line 130. The web 116 a provides resistance of theoutboard anchor assembly to rotation.

An energy absorbing system formed in accordance with teachings of thepresent invention may be mounted on or attached to either a concrete orasphalt foundation (not expressly shown). For some installations, anchorbolts 26 may vary in length from approximately seven inches (7″) toapproximately eighteen inches (18″). For some applications, holes (notexpressly shown) may be formed in an asphalt or concrete foundation toreceive respective anchor bolts 26. Various types of adhesive materialsmay also be placed within the holes to secure anchor bolts 26 in place.Preferably anchor bolts 26 do not extend substantially above the tops ofassociated nuts 27. Concrete and asphalt anchors and other fastenerssatisfactory for use in installing an energy absorbing systemincorporating teachings of the present invention are available fromHilti, Inc., at P.O. Box 21148, Tulsa, Okla. 74121.

Respective deflector plates or ramps 136 may be attached to eachoutboard anchor assembly 110 e-110 g in a direction extending towardsfirst end 21 of energy absorbing system 120. The ramps 136 extend fromthe mount guide plate 114 to the ground or to the level of the baseplate 112. Deflector plates or ramps 136 function in a manner similar topreviously described for ramps 36. If a vehicle should impact with side132 in the vicinity of outboard anchor assemblies 110 e-110 g, deflectorplates 136 will prevent the wheels of the vehicle from directlyimpacting or engaging outboard anchor assemblies 110 e-110 g. The ramps136 also serve in a collision to the first end 121, which collapses theenergy absorbing mechanism, as will be discussed in more detailhereinafter.

When energy absorbing system 120 is disposed in its first position,frame extensions 80 d-80 g are preferably disposed immediately adjacentto associated panel support frames 60 d-60 g. Various types ofmechanical fasteners, such as bolts 88 may be satisfactorily used toattach frame extensions 80 d-80 g with panel support frames 60 d-60 g.If a vehicle impacts second side 132 adjacent to frame extensions 80d-80 g, associated impact forces or kinetic energy will be transferredfrom frame extensions 80 d-80 g to outboard anchor assemblies 110 c-110g from respective hooks 117 and to adjacent panel support frames 60 d-60f, guide rail 209 and energy absorbing assemblies 186.

The outboard anchor assemblies 110 e-110 g are particularly useful whenthe second side 132 is impacted by a relatively tall vehicle, such as apickup. Referring to FIG. 21 to illustrate, the impact is typically onthe upper right panel 160 and tends to rotate the frame extension 80 fand the panel support frame 60 f counterclockwise about rails 208, 209.Such a rotation may impart an undesirable roll to the impacting vehicle.The hook 117 prevents rotation, thereby minimizing vehicle roll. Theimpacting vehicle is redirected onto the road in an upright condition.

An energy absorbing system with wing extensions formed in accordancewith teachings of the present invention may be expanded from a width ofapproximately twenty-four inches (24″) to any width required toaccommodate large or wide roadside hazards. For the embodimentrepresented by energy absorbing system 120, second portion 132 b ofsecond side 132 preferably includes a wing extension. The wing extensionof second portion 132 b may be formed in part by a plurality of panelsupport frames or wing extension support frames 360 and conventionalW-beam guardrail panels 260 such as ten (10) gauge guardrails. For someapplications, the length of panels 260 may be varied in increments fromapproximately twenty-eight inches (28″) to approximately two hundred andeighty inches (280″). Panels 260 preferably continue at approximatelythe same height extending from associated panels 160. See FIG. 20.

Panel support frames designated 360 h-360 m may be disposed between theend of rows 188 and 189 and an associated roadside hazard. See FIGS.19A, 20 and 24. Panel support frames 360 h-360 m may be securelyattached with an asphalt or concrete foundation (not expressly shown) orotherwise securely anchored in place. The number of panel support frames360 may be varied depending upon width of an associated roadside hazardand distance of the roadside hazard from the ends of guide rails 208 and209. For some applications, panel support frames 360 h-360 m may beinstalled on approximately twenty-eight inch (28″) centers.

For some applications each panel support frame 360 may have a generallytriangular configuration defined in part by respective post 362, wingextension base plate 364 and strut or brace 366. A plurality of anchorbolts 26 may be used to securely engage base plate 364 with anassociated concrete foundation. Each post 362 may have a cross sectionand dimensions associated with a typical highway guardrail support postor I-beam. Base plate 364 may be formed from the same material and havedimensions similar to crossties 24. Strut 366 may also be formed from anI-beam or other suitable type of highway structural material.

Energy absorbing system 120 as shown in FIG. 20 may include splices 262between overlapping panels 260 proximate panel support frame 360 j. Forsome applications wing extensions may be formed with panels 260 having alength corresponding with the distance between the end of panels 160 andan associated road side hazard to eliminate the need for splices 262.Also, panel support frames 360 and panels 260 may be preassembled (notexpressly shown) and delivered to a work site for installation as acomplete unit. An energy absorbing system may be relatively quicklyinstalled adjacent to a roadside hazard by using a preassembled modularbase unit and one or more preassembled wing extensions.

An energy absorbing system may be formed in accordance with teachings ofthe present invention having wing extensions which are secured in placeusing other types of support posts and supporting structures associatedwith highway guardrail safety systems. The present invention is notlimited to panel support frames 360. Wing extensions formed inaccordance with teachings of the present invention allow the use of agreater taper rate from the associated roadside hazard and the energyabsorbing assembly. As a result the overall length of an associatedenergy absorbing system may be substantially reduced while at the sametime providing the same or increased safety for an impacting vehicle andits occupants.

For some applications generally C-shaped channels may be attached topanel support frames 360. For the embodiment shown in FIG. 23, C-shapedchannel 368 may be disposed between lower panels 260 and associatedposts 362. Bolts 370 may be satisfactorily used to attach both panels260 and associated C-shaped channels 368 with posts 362. For someapplications C-shaped channels 368 provide required strength to allowthe associated wing extension to resist rail face impacts. For someapplications C-shaped channels (not expressly shown) may also beinstalled between the upper set of panels 260 and associated posts 362.Eight inch (8″) deep channels may be preferred for some applications.The channel 368 preferably extends for the full length of the set ofpanels.

Panels 160 are preferably slidably coupled with respective panelextensions 80 d-80 g in substantially the same manner as previouslydescribed with respect to panel support frames 60. Starting at panelsupport frame 360 j, conventional W-beams 260 may be securely attachedto and mounted on panel support frame 360 h-360 m. The number of panelsupport frames 360 and the number of panels 260 may be varied dependingupon the distance between the end of rows 188 and 189 and the associatedroadside hazard. Respective spliced joints 280 (See FIG. 29) may bedisposed between panels 160 and associated W-beams 260 at panel supportframe 360 j.

If panels 160 and/or 260 are hit, during a side impact, an impactingvehicle will be redirected back to the adjacent roadway and away fromthe associated roadside hazard. The vehicle impact may be transmittedfrom panels 160 directly to adjacent panel support frames 60 or to frameextensions 80 and then to panel support frames 60 depending upon thelocation of the side impact. Panel support frames 60 will attempt torotate, as panels 160 are usually hit high. However, panel supportframes 60 are prevented from rotating on guide rails 208 and 209 byinwardly extending projections or tabs 67 underneath beam guides on therails.

Referring to FIG. 23, the vehicle impact, during a side impact, may betransmitted from W-beam panels 260 directly to adjacent panel supportframes 360 h-360 m. Panel support frames 360 h-360 m are prevented fromrotation by associated strut 366 and base plate 364. Both crossties 24and base plates 364 may bend or be deformed by a side impact. Thus, thesystem “gives” during a side impact by allowing crossties 24 and baseplates 364 to deform. Much like the system's collapse during a head oncollision, this “give” on a lateral or side impact reduces decelerationforces applied to a side impacting vehicle. Systems 120, 120 a and 420generally remain in place after a redirecting lateral or side impact.

FIGS. 24 and 25 are schematic drawings showing various features ofenergy absorbing system 120 a. Energy absorbing system 120 a includesfirst end 121 facing oncoming traffic and second end 122 c disposedadjacent to an associated roadside hazard (not expressly shown). Firstend 121 of energy absorbing system 120 and 120 a may have substantiallythe same configuration and dimensions. Energy absorbing system 120 aalso includes first side 131 c and second side 132. First side 131 c maybe described as having a left side flare. Second side 132 may bedescribed as having a right side flare. For the embodiment representedby energy absorbing system 120 a first side 131 c and second side 132may have substantially the same configurations and dimensions except forrespective left side flare and the right side flare. Second side 132 ofenergy absorbing systems 120 and 120 a may also have substantially thesame configuration and dimensions based in part of the distance betweenthe end of rows 188 and 189 and an associated roadside hazard.

Various components of energy absorbing system 120 a may be generallysymmetrically disposed with respect to center line 130. First side 131 cand second side 132 extend generally parallel with each other along atleast a portion of associated guide rails 208 and 209. First portion 131a of first side 131 c and first portion 132 a of second side 132 extendgenerally parallel with each other from first end 121 along at least aportion of center line 130. Second portion 131 b of first side 131 c maybe disposed at approximately the same angle relative to first portion131 a. Second portion 132 b of second side 132 may be disposed atapproximately the same angle relative to first portion 132 a.

When energy absorbing system 120 a is in its first position, sledassembly 40 will be slidably disposed at first end 121 facing oncomingtraffic. Second end 122 c of energy absorbing system 120 a may bedisposed adjacent to a relatively large, wide roadside hazard (notexpressly shown). Second end 122 a of first side 131 c and second end122 b of second side 132 may be attached with a concrete barrier orother portions of a conventional guardrail system (not expressly shown).Portion 131 b of first side 131 c and portion 132 b of second side 132may both be disposed at approximately the same angle relative tolongitudinal center line 130. Proximate panel support frame 60 c, bothportion 131 b of first side 131 c and portion 132 b of second side 132may be disposed at approximately seven degrees (7°) relative to portion131 a and portion 132 a.

Second portion 131 b of first side 131 c preferably includes a secondgroup of panel support frames designated 360 h-360 m and multiple panels260 securely attached thereto as previously described with respect toenergy absorbing system 120. As shown in FIG. 25 a pair of sideextensions 80 f are preferably disposed on opposite sides of panelsupport frame 60 f. Associated panels 160 may be slidably attached withrespective side extensions 80 f.

When an impacting vehicle strikes the first end 121 of the energyabsorbing system 120, 120 a, the sled 40 is moved and the energyabsorbing assembly engages. The panel support frames 60 a-60 b movealong the guide rails 208, 209, and the panels 160 attached theretotelescope along the axis of the guide rails, as discussed above. As thesled continues to move along the guide rails, panel support frames 60c-60 f will likewise begin to move in sequential manner, also along theguide rails. As panel support frame 60 c moves toward the second end122, panel 160 cc (see FIG. 19B) telescopes over panel 160 dd.

The panels 160 change their orientation to the guide rails 208, 209,becoming less parallel and more perpendicular. The coupling between thejoint plates 74 and the straps 166 bend and allow the panels to changeorientation so as to increase the angle with respect to the center line130. The sliding connection formed by the slot plate 170 (see FIG. 15)allows the downstream end of the panels to uncouple to further assist inthe panels changing orientation due to a first end impact.

The frame extensions 80 d-80 g generally move in unison with therespective associated panel support frames 60 d-60 g. The frameextensions move in a direction generally parallel to the guide rails208, 209. Each hook 117 (see FIG. 22) moves in unison with therespective frame extensions. The hooks 117 move toward the second end122 (to the right in the orientation of FIG. 22), moving beneath theirinitial mount guide plate 114. Each hook 117 clears the respective mountguide plate 114 and continues its motion, contacting the ramp 136 thatis located downstream. The hook 117 rides the ramp 136, lifting itsassociated panel extension and the panel support frame. As shown in FIG.21, there is vertical clearance between the tabs 67 and the guide rails208, 209, wherein the panel support frames 60 can elevate slightly fromthe guide rails, to enable the hooks 117 to elevate on the ramps 136.

Referring back to FIG. 22, as the panel support frame continues to movealong the guide rails, the hook slides from the ramp along the top ofthe mount guide plate and then falls from the trailing, or downstream,edge of the mount guide plate 114. The hook moves further downstream andcontacts the next ramp, repeating the process.

As shown in FIG. 19A, the outboard anchor assemblies 110 e-110 g arespaced increasingly further away from the guide rails, in the directionof traffic. Thus, a hook 117 (such as the hook connected to frameextension 80 e) may pass between the guide rail 209 and an outboardanchor assembly (such as outboard anchor assembly 110 g) withouttraversing up the ramp 136. The ramp 136 preferably has a tapered inneredge 136 a (see FIG. 25) that faces the guide rails. The passing hook117 may contact the inner edge 136 a and be forced toward the guiderails. The outboard anchor assemblies that are positioned downstream maybe spaced far enough apart that the hooks 117 on an upstream panel mayavoid contact with those downstream outboard anchor assemblies. By wayof example, as shown in FIG. 24, the hooks couple to the panel supportframe 60 e, and by way of its associated frame extensions 80 e, ride theramps upon the outboard anchor assemblies 110 f, and pass between theoutboard anchor assemblies 110 g. Thus, the outboard anchor assemblies,while operating during a side impact to the energy absorbing system, donot interfere with a nose impact collapse of the system.

The tapered inner edge 136 a, which is on the same side as the web 116a, also serves as a visual reference to ensure that the web 116 a islocated inboard, so as not to interfere with the motion of the hook 117in a first end 121 impact.

Because portion 131 b of first side 131 c and portion 132 b of secondside 132 are at an angle with respect to the guide rails, and even inmany circumstances, at an angle with respect to the direction ofvehicular traffic, reinforcement of the panels 160 is desired tominimize the possibility of a vehicle passing through the panels.

At least one cable assembly and preferably two or more cable assembliesmay be coupled with sled assembly 40 and at least a portion of the firstside and/or second side of an associated energy absorbing system. Eachcable assembly may include one or more cables, multiple cable clamps andmultiple clamp plates. As shown in FIGS. 19A, and 24-28B first cable 501and second cable 502 may extend longitudinally along associated panels160 from panel support frames 360 h to associated sled assembly 40. Thefree ends of cables 501 and 502 may be secured with respective posts 362in the wing extensions using various techniques such as cable clamps510. See FIG. 27. First cable 501 may extend along the panels on thefirst side 131 c (see FIG. 24) toward the first end 121. At the panelsupport frame 60 a, the first cable 501 crosses over the guide rails208, 209 to wrap around an upright at second end 42 of sled assembly 40and loop back to the wing extension on the first side by extendingdiagonally thereacross to approximately the location of panel supportframe 60 a. Second cable 502 follows a similar path along the secondside 132 and may be wrapped around an opposite upright at second end 42of sled assembly 40 and extend diagonally thereacross to a positionproximate panel support frame 60 a. First cable 501 and second cable 502provide additional tension support to help respective first side 131 andsecond side 132 resist side impacts. For some applications cables 501and 502 may be formed with wire rope having a diameter of approximatelyone-half of an inch.

First cable 501 and second cable 502 provide additional anchorage andtensile strength to allow respective sides 131, 131 c and 132 tosatisfactorily redirect a vehicle impacting at approximately twentydegrees (20°) with portions of sides 131, 131 c and/or 132 flared at anangle of approximately seven degrees (7°). Portions of cables 501 and502 may be threaded between the humps of respective panels 160 from adownstream location proximate panel support frame 360 h to a respectiveupright associated with sled assembly 40. Each cable 501 and 502 maythen be returned through the humps of a lower panel to panel supportframe 360 h.

FIGS. 28A and 28B show portions of cable 502 adjacent to frame extension80 d. For this embodiment respective clamp plates 504 may be securelyattached with associated bent plate 74. A generally U-shaped cable clamp506 may be inserted through an opening 508 formed in each clamp plate504 to secure a portion of cable 502 at the desired location relative topanel 160 and panel support frame 60 c.

The cables 501, 502 are preferably coupled to each of the panel supportframes 60 a-60 c and the frame extensions 80 d-80 g. The ends of thecables can be coupled to the downstream-most frame extension, or to theroadside hazard itself. The cables can also be extended into the wingextension panels 260.

Energy absorbing system 420 as shown in FIGS. 30 and 31 demonstratesthat the flare of first side 431 and second side 432 may start at firstend 121. Energy absorbing system 420 is also another example of anenergy absorbing system formed in accordance with teachings of thepresent invention with asymmetrical sides.

A plurality of split panel support frames 460 a-460 i may be used withenergy absorbing system 420 to allow respective sides 431 and 432 to beflared at various angles and to accommodate various widths as desired.Split panel support frames 460 a and 460 b may be slidably attached withguide rail 208. Split panel support frames 460 c-460 i may be slidablyattached to guide rail 209. The dimensions and configurations associatedwith split panel support frames 460 may be varied as required toaccommodate the angle or flare of respective sides 431 and 432.Respective outboard anchor assemblies 110 may also be provided asrequired for each split panel support frame 460.

Cables, such as 501 and 502 previously discussed, can be used with theenergy absorbing system 420.

Hinges 430 couple the sides 431, 432 to the first end 121 of the energyabsorbing system 420. The hinges 430, which are of the pin type, allowthe sides 431, 432 to be moved to the desired angle. For each side, thehinges are coupled to the straps 166 inside of the panels 160 and to thefirst end upright 41, 43 of the sled assembly 40. The uprights can beangle posts, much like the uprights 44, 45 on the downstream side of thesled assembly.

The hinges 430 not only serve as hinges during installation of theenergy absorbing system 420, but serve as hinges during a vehicle impactwith the first end 121. As the sled assembly 40 moves along the guiderails 208, 209, the angle that the panels 160 on each side make with thecenter line 130 changes, as allowed by the hinges 430.

The split panel support frames allow the angle of the individual sidesto be independently adjusted with respect to the guide rails 208, 209and to the opposite side. With the split panel support frames, the firstside 431 has a set of parallel support frames that are independent ofthe set of panel support frames that connect to the second side 432. Thesplit panel support frames can also be used as an alternative to thepanel extensions 80 of systems 120, 120 a of FIGS. 19A and 24.

One example of a split panel support frame satisfactory for use with thepresent invention is shown in FIG. 31. Split panel support frame 460 hmay be slidably engaged with or slidably disposed on guide rail 209 andoutboard anchor assembly 110 h. Outboard anchor assembly 110 h providesadditional support for split panel support frame 460 h.

Split panel support frames 460 may have two components designated 461and 462. For some applications each split panel support frame 460 mayinclude respective first component 461 with approximately the sameoverall configuration and dimensions. The configuration and dimensionsof second component 462 may be varied to accommodate the flare orspacing between sides 431 and 432 and respective guide rails 208 and209. Bolts 88 may be used to attach first component 461 with secondcomponent 462. Each split panel support frame 460 may include respectivepost 468 having dimensions and an overall configuration correspondingwith post 68 or 69 of panel support frames 60. For the embodiment shownin FIG. 31, each component 461 h and 462 h may be described as having agenerally triangular cross-section or configuration.

As shown in FIG. 31, the split panel support frame 460 c can simply bearon the guide rail 209 and on the respective outboard anchor assembly 110h. During a side impact with the panels 160, the hook 117 and outboardanchor assembly prevent the split panel support frame from moving intoward the guide rail 209. Rotation of the split panel support frame,and consequently of the panels 160, is prevented by the hook 117engaging the outboard anchor assembly 110 h and the first component 461h bearing on the guide rail 209. During an impact with the first end 121of the system 420, the split panel frame moves off of the outboardanchor assembly 110 and slides along the guide rail toward the secondend 122.

The split panel frame can be used without the first component 461, asillustrated by split panel frames 460 c-460 g of FIG. 30, wherein thesecond component bears on the guide rail. The first component 461 formsan inward extension and is used on split panel support frames 406 a-460b, 460 h-460 i.

Split panel support frames 460 j-460 n utilize the first component 461as a leg. The first component 461 extends down to bear on the ground(see the dash lines in FIG. 31). The first component 461 is bolted tothe bottom of the second component 462.

A variety of configurations of the split panel support frames can beutilized. FIG. 30 is for illustrative purposes only. The split panelsupport frames support the panels 160, resist side impacts bycooperating with the outboard anchor assemblies 110 and allow themovement of the system along the center line 130 during an impact to thefirst end 121. The divergence of each side can be adjusted independentlyof the other side. In FIG. 30, the side 431 has a larger divergence thandoes the side 432.

Although the present invention has been described in detail, it shouldbe understood that various changes, substitutions and alterations can bemade hereto without departing from the spirit and scope of the inventionas defined by the appended claims.

1-54. (canceled)
 55. A crash cushion operable to minimize the results ofa collision between a vehicle and a roadside hazard, comprising: anenergy absorbing assembly extending in a first direction from a firstend of the crash cushion; a sled assembly located proximate the firstend and operable to move in the first direction to absorb energy from avehicle impacting the first end of the crash cushion; a first group ofpanels extending generally in the first direction from the first end ofthe crash cushion; a second group of panels extending generally in thefirst direction from the first end of the crash cushion; the first groupof panels and the second group of panels spaced from each other anddisposed on opposite sides of the energy absorbing assembly; and atleast a first portion of the panels and a second portion of the panelsintersecting with each other at an angle extending from the firstdirection whereby the distance between the first portion of the panelsand the second portion of the panels increases in the first direction.56. The crash cushion of claim 55 wherein the energy absorbing assemblyfurther comprises two generally parallel, spaced apart tracks extendingfrom the first end in the first direction.
 57. The crash cushion ofclaim 55 further comprising: a plurality of panel support framesextending in the first direction from the first end of the crashcushion; a first group of the panel support frames operable to collapsetowards the first direction when a vehicle impacts the sled assembly; asecond group of panel support frames disposed between the energyabsorbing assembly and the roadside hazard; the second group of panelsupport frames spaced from each other and securely anchored in place toresist a vehicle impact; and the panel support frames cooperating withthe panels to redirect a vehicle impacting with either side of the crashcushion.
 58. The crash cushion of claim 55 further comprising: aplurality of support frames spaced from each other and extending fromthe first end of the crash cushion; each panel having a first, upstreamend and a second, downstream end with a slot extending from a locationnear the respective first, upstream end to a location near therespective second, downstream end; the panels coupled with the supportframes in an overlapping manner whereby the second, downstream end ofone panel overlaps the first, upstream end of the adjacent panel; thefirst, upstream end of each panel securely coupled to one of the supportframes by a respective fastener; and each fastener having a standoffsized to be received by the slot near the downstream end of the onepanel.
 59. The crash cushion of claim 55 further comprising: a pluralityof support frames spaced from each other and extending from the firstend of the crash cushion; at least one of the panel support frameshaving a first side and a second side; and two panels respectivelyattached to the first side and two panels respectively attached to thesecond side the at least one panel support frame.
 60. The crash cushionof claim 55 further comprising: at least one cable assembly securelyattached with the sled assembly; the at least one cable assemblyextending generally in the first direction from the sled assembly to apanel support frame located proximate the intersection of the firstportion of the panels with the second portion of the panels forming theangle; and the sled assembly and the cable assembly cooperating witheach other to maintain desired tension on the associated panels when thesled assembly is disposed proximate the first end of the crash cushion.61. The crash cushion of claim 60 further comprising: a second cableassembly securely engaged with the sled assembly and extending generallyin the first direction to another support frame disposed on an oppositeside of the crash cushion; and the sled assembly and the second cableassembly cooperating with each other to maintain desired tension on theassociated panels extending along the opposite side of the crashcushion.
 62. The crash cushion of claim 55 further comprising: alongitudinal axis extending in the first direction from the first end;and the first group of panels and the second group of panels disposed ina generally symmetrical configuration relative to the longitudinal axis.63. An energy absorbing system operable to minimize results of acollision between a moving vehicle and a roadside hazard, the energyabsorbing system comprising: a first end and a second end with thesecond end disposed adjacent to a roadside hazard and the first endextending longitudinally from the roadside hazard in a first directiontoward oncoming traffic; a first side and a second side spaced from eachother and extending between the first end and the second end of thesystem; at least portions of the first side and the second side disposedat angles relative to each other whereby the spacing between the firstside and the second side at the second end is greater than the spacingbetween the first side and the second side at the first end; and atleast one energy absorbing assembly disposed at the first end of theenergy absorbing system such that collision of a vehicle with the firstend will dissipate kinetic energy of the vehicle.
 64. The energyabsorbing system of claim 63 further comprising: a longitudinal axisextending between the first end to the second end; at least a portion ofthe first side extending at a first angle relative to the longitudinalaxis; and at least a portion of the second side extending at a secondangle relative to the longitudinal axis.
 65. The energy absorbing systemof claim 64 further comprising the first angle approximately equal tothe second angle.
 66. The energy absorbing system of claim 64 furthercomprising the first angle larger than the second angle.
 67. The energyabsorbing system of claim 63 further comprising the first side startingat the first end extending at the angle relative to the longitudinalaxis.
 68. The energy absorbing system of claim 63 further comprising:the first side starting at the first end extending at a first anglerelative to the longitudinal axis; and the second side starting at thefirst end extending at a second angle relative to the longitudinal axis.69. The energy absorbing system of claim 63 further comprising the firstside and the second side having a generally symmetrical relationshipwith each other.
 70. The energy absorbing system of claim 63 furthercomprising the first side having at least one wing extension.
 71. Theenergy absorbing system of claim 63 further comprising: the first sidehaving a respective wing extension; and the second side having arespective wing extension.
 72. The energy absorbing system of claim 63further comprising: at least one wing extension formed in part fromconventional W-beam guardrail panels; and a plurality of panel supportframes.
 73. The energy absorbing system of claim 72 wherein each panelsupport frame further comprises a support post, a support plate and astrut disposed at an angle between the support plate and the supportpost.
 74. A crash cushion operable to minimize the results of acollision between a vehicle and a roadside hazard, comprising: an energyabsorbing assembly extending in a first direction from a first end ofthe crash cushion; a portion of the energy absorbing assembly operableto move in the first direction to dissipate energy from a vehiclecollision with the first end of the crash cushion; a first group ofpanels located on one side of the energy absorbing assembly andextending generally in the first direction from the first end; a secondgroup of panels located on an opposite side of the energy absorbingassembly and extending generally in the first direction from the firstend; the second group of panels having a movable subsection operable tomove generally in the first direction when the portion of the energyabsorbing assembly moves in the first direction; the second group ofpanels having a fixed subsection; and the movable subsection of thesecond group of panels disposed between the first end of the crashcushion and the fixed subsection.
 75. An energy absorbing systemoperable to minimize results of a collision between a vehicle and aroadside hazard, comprising: an energy absorbing assembly extending in afirst direction from a first end of the system; a first side located onone side of the energy absorbing assembly; a second side located onanother side of the energy absorbing assembly; the first side and thesecond side having respective panels; the first side and the second sideoperable to resist an impact by a vehicle to the respective first sideand second side; portions of the first side and portions of the secondside operable to move generally in the first direction when a vehicleimpacts the first end of the system; and at least one portion of thefirst side being uncoupled from the second side with the at least oneuncoupled portion of the first side oriented with respect to the firstdirection independently of the second side.
 76. The crash cushion ofclaim 75 further comprising: a plurality of panel support frames coupledto the panels of the first side and the second side; and the panelsupport frames coupled to the at least one portion of the first sideseparate from the panel support frames coupled to the second side. 77.The crash cushion of claim 76 further comprising at least one of thepanel support frames coupled to a portion of the first side contactingthe energy absorbing assembly.
 78. The crash cushion of claim 75 furthercomprising at least one of the panel support frames coupled to the atleast one portion of the first side bearing on the ground.
 79. The crashcushion of claim 75 further comprising the panel support frames of theat least one portion of the first side coupled to at least one outboardanchor to resist vehicle impacts to the first side.
 80. A crash cushionoperable to minimize the results of a collision between a vehicle and aroadside hazard, comprising: an energy absorbing assembly extending in afirst direction from a first end of the crash cushion; portions of theenergy absorbing assembly operable to move in the first direction when avehicle impacts the first end; a plurality of panel support framesoperable to move in the first direction; a plurality of panels attachedto the panel support frames; a portion of the panels diverging from thefirst direction as the panels extend from the first end; selected panelshaving channels attached thereto; a cable extending through at least oneof the channels associated with the diverging panels; and the cableanchored at a location toward the first end and also at a location awayfrom the first end.
 81. The crash cushion of claim 80 further comprisingthe cables coupled to selected panel support frames.
 82. The crashcushion of claim 80 wherein the energy absorbing assembly furthercomprises: a moveable sled disposed at the first end; and the cableanchored at the location toward the first end anchored engaged with thesled.
 83. The crash cushion of claim 80 further comprising the panelsupport frames slidably coupled to outboard anchors operable to resistrotation when a vehicle impacts the panels.
 84. A crash cushion operableto minimize the results of a collision between a vehicle and a roadsidehazard, comprising: an energy absorbing assembly extending in a firstdirection from a first end of the crash cushion, the energy absorbingassembly moveable in the first direction when a vehicle impacts thefirst end; panel support frames moveable in the first direction; panelsattached to the panel support frames, the panels diverging from thefirst direction as the panels extend from the first end; and the panelsupport frames slidably coupled to anchors operable to resist rotationwhen a vehicle impacts the panels.
 85. The crash cushion of claim 84further comprising at least one of the panel support frames slidablycoupled to the anchors with at least one of the panel support framesbearing on the energy absorbing assembly and coupled to an outboardanchor.
 86. The crash cushion of claim 84 wherein the panel supportframes further comprise: at least one respective hook located in achannel; and the channel oriented in the first direction.
 87. A crashcushion operable to minimize the results of a collision between avehicle and a roadside hazard, comprising: an energy absorbing assemblyextending in a first direction from a first end of the crash cushion; asled assembly located proximate the first end and operable to move inthe first direction to absorb energy from a vehicle impacting the firstend of the crash cushion; a first group of panels extending generally inthe first direction from the first end of the crash cushion; a secondgroup of panels extending generally in the first direction from thefirst end of the crash cushion; the first group of panels and the secondgroup of panels spaced from each other and disposed on opposite sides ofthe energy absorbing assembly; first group of panels defining in part afirst side of the crash cushion; the second group of panels defining inpart a second side of the crash cushion; at least a first portion of thepanels of the first side and a first portion of the panels of the secondside extending generally parallel with each other in the firstdirection; a second portion of the panels of the second sideintersecting with the first portion of the panels of the second side atan angle extending from the first direction; and the second portion ofthe panels of the second side spaced from a second portion of the panelsof the first side by an increasing distance in the first direction.